MFS SERIES TRUST IV (0000063068) (Filer)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number

811-02594

MFS SERIES TRUST IV

(Exact name of registrant as specified in charter)

111 Huntington Avenue, Boston, Massachusetts 02199

(Address of principal executive offices) (Zip code)

Christopher R. Bohane

Massachusetts Financial Services Company

111 Huntington Avenue

Boston, Massachusetts 02199

(Name and address of agents for service)

Registrant's telephone number, including area code:

(617) 954-5000

Date of fiscal year end:

August 31

Date of reporting period:

August 31, 2026

ITEM 1.  REPORTS TO STOCKHOLDERS.

Item 1(a):

MFS^® Blended Research^® Emerging Markets Equity Fund

Class A-BRKAX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class A shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 42.83%, at net asset value. This compares with a return of 39.25% for the fund’s benchmark, the MSCI Emerging Markets Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI Emerging Markets Index:

  • Security selection and an underweight position in the information technology sector contributed to the fund's relative performance.

  • Stock selection within the industrials, financials and energy sectors also supported relative results.

• Top detractors from performance relative to the MSCI Emerging Markets Index:

  • Stock selection within the materials sector held back relative performance.

  • Stock selection and an overweight position in the communication services sector further weighed on the fund's relative returns.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class A over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

If the 1-year without sales charge return included adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles, the return would be 42.92%.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/a for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective March 1, 2026, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.45% up to $5 billion; and 0.40% in excess of $5 billion.

Effective March 1, 2026, for Class A shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 0.85% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRKA-ANN

MFS^® Blended Research^® Emerging Markets Equity Fund

Class B-BRKBX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class B shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 41.82%, at net asset value. This compares with a return of 39.25% for the fund’s benchmark, the MSCI Emerging Markets Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI Emerging Markets Index:

  • Security selection and an underweight position in the information technology sector contributed to the fund's relative performance.

  • Stock selection within the industrials, financials and energy sectors also supported relative results.

• Top detractors from performance relative to the MSCI Emerging Markets Index:

  • Stock selection within the materials sector held back relative performance.

  • Stock selection and an overweight position in the communication services sector further weighed on the fund's relative returns.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class B over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

CDSC – Contingent Deferred Sales Charge.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/b for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective March 1, 2026, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.45% up to $5 billion; and 0.40% in excess of $5 billion.

Effective March 1, 2026, for Class B shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 1.60% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRKB-ANN

MFS^® Blended Research^® Emerging Markets Equity Fund

Class C-BRKCX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class C shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 41.77%, at net asset value. This compares with a return of 39.25% for the fund’s benchmark, the MSCI Emerging Markets Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI Emerging Markets Index:

  • Security selection and an underweight position in the information technology sector contributed to the fund's relative performance.

  • Stock selection within the industrials, financials and energy sectors also supported relative results.

• Top detractors from performance relative to the MSCI Emerging Markets Index:

  • Stock selection within the materials sector held back relative performance.

  • Stock selection and an overweight position in the communication services sector further weighed on the fund's relative returns.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class C over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

CDSC – Contingent Deferred Sales Charge.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/c for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective March 1, 2026, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.45% up to $5 billion; and 0.40% in excess of $5 billion.

Effective March 1, 2026, for Class C shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 1.60% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRKC-ANN

MFS^® Blended Research^® Emerging Markets Equity Fund

Class I-BRKIX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class I shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 43.23%, at net asset value. This compares with a return of 39.25% for the fund’s benchmark, the MSCI Emerging Markets Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI Emerging Markets Index:

  • Security selection and an underweight position in the information technology sector contributed to the fund's relative performance.

  • Stock selection within the industrials, financials and energy sectors also supported relative results.

• Top detractors from performance relative to the MSCI Emerging Markets Index:

  • Stock selection within the materials sector held back relative performance.

  • Stock selection and an overweight position in the communication services sector further weighed on the fund's relative returns.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class I over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/i for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective March 1, 2026, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.45% up to $5 billion; and 0.40% in excess of $5 billion.

Effective March 1, 2026, for Class I shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 0.60% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRKI-ANN

MFS^® Blended Research^® Emerging Markets Equity Fund

Class R1-BRKRX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

For the period from September 1, 2025 through August 31, 2026, the distribution fee was not imposed. Had the distribution fee been imposed throughout the entire period, the “Costs of a $10,000 investment” and the “Costs paid as a percentage of a $10,000 investment” would have been approximately $216 and 1.78%, respectively.

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class R1 shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 42.90%, at net asset value. This compares with a return of 39.25% for the fund’s benchmark, the MSCI Emerging Markets Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI Emerging Markets Index:

  • Security selection and an underweight position in the information technology sector contributed to the fund's relative performance.

  • Stock selection within the industrials, financials and energy sectors also supported relative results.

• Top detractors from performance relative to the MSCI Emerging Markets Index:

  • Stock selection within the materials sector held back relative performance.

  • Stock selection and an overweight position in the communication services sector further weighed on the fund's relative returns.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class R1 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/r1 for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective March 1, 2026, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.45% up to $5 billion; and 0.40% in excess of $5 billion.

Effective March 1, 2026, for Class R1 shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 1.60% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRKR1-ANN

MFS^® Blended Research^® Emerging Markets Equity Fund

Class R2-BRKSX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class R2 shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 42.47%, at net asset value. This compares with a return of 39.25% for the fund’s benchmark, the MSCI Emerging Markets Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI Emerging Markets Index:

  • Security selection and an underweight position in the information technology sector contributed to the fund's relative performance.

  • Stock selection within the industrials, financials and energy sectors also supported relative results.

• Top detractors from performance relative to the MSCI Emerging Markets Index:

  • Stock selection within the materials sector held back relative performance.

  • Stock selection and an overweight position in the communication services sector further weighed on the fund's relative returns.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class R2 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/r2 for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective March 1, 2026, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.45% up to $5 billion; and 0.40% in excess of $5 billion.

Effective March 1, 2026, for Class R2 shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 1.10% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRKR2-ANN

MFS^® Blended Research^® Emerging Markets Equity Fund

Class R3-BRKTX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class R3 shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 42.85%, at net asset value. This compares with a return of 39.25% for the fund’s benchmark, the MSCI Emerging Markets Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI Emerging Markets Index:

  • Security selection and an underweight position in the information technology sector contributed to the fund's relative performance.

  • Stock selection within the industrials, financials and energy sectors also supported relative results.

• Top detractors from performance relative to the MSCI Emerging Markets Index:

  • Stock selection within the materials sector held back relative performance.

  • Stock selection and an overweight position in the communication services sector further weighed on the fund's relative returns.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class R3 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/r3 for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective March 1, 2026, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.45% up to $5 billion; and 0.40% in excess of $5 billion.

Effective March 1, 2026, for Class R3 shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 0.85% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRKR3-ANN

MFS^® Blended Research^® Emerging Markets Equity Fund

Class R4-BRKUX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class R4 shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 43.25%, at net asset value. This compares with a return of 39.25% for the fund’s benchmark, the MSCI Emerging Markets Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI Emerging Markets Index:

  • Security selection and an underweight position in the information technology sector contributed to the fund's relative performance.

  • Stock selection within the industrials, financials and energy sectors also supported relative results.

• Top detractors from performance relative to the MSCI Emerging Markets Index:

  • Stock selection within the materials sector held back relative performance.

  • Stock selection and an overweight position in the communication services sector further weighed on the fund's relative returns.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class R4 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/r4 for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective March 1, 2026, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.45% up to $5 billion; and 0.40% in excess of $5 billion.

Effective March 1, 2026, for Class R4 shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 0.60% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRKR4-ANN

MFS^® Blended Research^® Emerging Markets Equity Fund

Class R6-BRKVX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research Emerging Markets Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class R6 shares of the MFS Blended Research Emerging Markets Equity Fund (fund) provided a total return of 43.33%, at net asset value. This compares with a return of 39.25% for the fund’s benchmark, the MSCI Emerging Markets Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI Emerging Markets Index:

  • Security selection and an underweight position in the information technology sector contributed to the fund's relative performance.

  • Stock selection within the industrials, financials and energy sectors also supported relative results.

• Top detractors from performance relative to the MSCI Emerging Markets Index:

  • Stock selection within the materials sector held back relative performance.

  • Stock selection and an overweight position in the communication services sector further weighed on the fund's relative returns.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class R6 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/r6 for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective March 1, 2026, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.45% up to $5 billion; and 0.40% in excess of $5 billion.

Effective March 1, 2026, for Class R6 shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 0.54% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRKR6-ANN

MFS^® Blended Research^®
International Equity Fund

Class A-BRXAX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class A shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 32.58%, at net asset value. This compares with a return of 27.35% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection within the industrials and financials sectors benefited the fund's relative performance.

• Top detractors from performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection and an overweight position in the communication services sector weakened relative performance.

  • Stock selection within the real estate sector also weighed on the fund's relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class A over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance. This graph includes the deduction of the maximum applicable sales charge.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/a for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective October 1, 2025, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.35% up to $5 billion; and 0.325% in excess of $5 billion.

Effective October 1, 2025, for Class A shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 0.77% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRXA-ANN

MFS^® Blended Research^®
International Equity Fund

Class B-BRXBX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class B shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 31.57%, at net asset value. This compares with a return of 27.35% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection within the industrials and financials sectors benefited the fund's relative performance.

• Top detractors from performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection and an overweight position in the communication services sector weakened relative performance.

  • Stock selection within the real estate sector also weighed on the fund's relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class B over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

CDSC – Contingent Deferred Sales Charge.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/b for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective October 1, 2025, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.35% up to $5 billion; and 0.325% in excess of $5 billion.

Effective October 1, 2025, for Class B shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 1.52% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRXB-ANN

MFS^® Blended Research^®
International Equity Fund

Class C-BRXCX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class C shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 31.61%, at net asset value. This compares with a return of 27.35% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection within the industrials and financials sectors benefited the fund's relative performance.

• Top detractors from performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection and an overweight position in the communication services sector weakened relative performance.

  • Stock selection within the real estate sector also weighed on the fund's relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class C over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

CDSC – Contingent Deferred Sales Charge.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/c for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective October 1, 2025, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.35% up to $5 billion; and 0.325% in excess of $5 billion.

Effective October 1, 2025, for Class C shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 1.52% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRXC-ANN

MFS^® Blended Research^®
International Equity Fund

Class I-BRXIX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class I shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 32.97%, at net asset value. This compares with a return of 27.35% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection within the industrials and financials sectors benefited the fund's relative performance.

• Top detractors from performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection and an overweight position in the communication services sector weakened relative performance.

  • Stock selection within the real estate sector also weighed on the fund's relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class I over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/i for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective October 1, 2025, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.35% up to $5 billion; and 0.325% in excess of $5 billion.

Effective October 1, 2025, for Class I shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 0.52% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRXI-ANN

MFS^® Blended Research^®
International Equity Fund

Class R1-BRXRX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class R1 shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 31.68%, at net asset value. This compares with a return of 27.35% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection within the industrials and financials sectors benefited the fund's relative performance.

• Top detractors from performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection and an overweight position in the communication services sector weakened relative performance.

  • Stock selection within the real estate sector also weighed on the fund's relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class R1 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/r1 for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective October 1, 2025, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.35% up to $5 billion; and 0.325% in excess of $5 billion.

Effective October 1, 2025, for Class R1 shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 1.52% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRXR1-ANN

MFS^® Blended Research^®
International Equity Fund

Class R2-BRXSX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class R2 shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 32.25%, at net asset value. This compares with a return of 27.35% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection within the industrials and financials sectors benefited the fund's relative performance.

• Top detractors from performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection and an overweight position in the communication services sector weakened relative performance.

  • Stock selection within the real estate sector also weighed on the fund's relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class R2 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/r2 for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective October 1, 2025, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.35% up to $5 billion; and 0.325% in excess of $5 billion.

Effective October 1, 2025, for Class R2 shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 1.02% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRXR2-ANN

MFS^® Blended Research^®
International Equity Fund

Class R3-BRXTX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class R3 shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 32.63%, at net asset value. This compares with a return of 27.35% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection within the industrials and financials sectors benefited the fund's relative performance.

• Top detractors from performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection and an overweight position in the communication services sector weakened relative performance.

  • Stock selection within the real estate sector also weighed on the fund's relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class R3 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/r3 for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective October 1, 2025, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.35% up to $5 billion; and 0.325% in excess of $5 billion.

Effective October 1, 2025, for Class R3 shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 0.77% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRXR3-ANN

MFS^® Blended Research^®
International Equity Fund

Class R4-BRXUX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class R4 shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 32.93%, at net asset value. This compares with a return of 27.35% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection within the industrials and financials sectors benefited the fund's relative performance.

• Top detractors from performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection and an overweight position in the communication services sector weakened relative performance.

  • Stock selection within the real estate sector also weighed on the fund's relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class R4 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/r4 for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective October 1, 2025, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.35% up to $5 billion; and 0.325% in excess of $5 billion.

Effective October 1, 2025, for Class R4 shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 0.52% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRXR4-ANN

MFS^® Blended Research^®
International Equity Fund

Class R6-BRXVX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Blended Research International Equity Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class R6 shares of the MFS Blended Research International Equity Fund (fund) provided a total return of 33.07%, at net asset value. This compares with a return of 27.35% for the fund’s benchmark, the MSCI All Country World (ex-US) Index (net div).

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection within the industrials and financials sectors benefited the fund's relative performance.

• Top detractors from performance relative to the MSCI All Country World (ex-US) Index:

  • Stock selection and an overweight position in the communication services sector weakened relative performance.

  • Stock selection within the real estate sector also weighed on the fund's relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class R6 over a ten year period or since inception, if shorter, in comparison to a broad measure of market performance.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of a broad measure of market performance over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/r6 for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective October 1, 2025, the management fee is computed daily and paid monthly at the following annual rates based on the fund’s average daily net assets: 0.35% up to $5 billion; and 0.325% in excess of $5 billion.

Effective October 1, 2025, for Class R6 shares, the investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, excluding interest, taxes, extraordinary expenses, brokerage and transaction costs, certain tax reclaim recovery expenses (including contingency fees and closing agreement expenses), and investment-related expenses, such that total operating expenses do not exceed 0.43% annually of the class’s average daily net assets. This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until December 31, 2027.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

BRXR6-ANN

MFS^® Global New Discovery Fund

Class A-GLNAX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class A shares of the MFS Global New Discovery Fund (fund) provided a total return of 6.58%, at net asset value. This compares with a return of 22.35% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 19.70%.

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and underweight positions in both the real estate and financials sectors aided relative performance.

  • The fund's avoidance of the utilities sector also benefited relative returns.

• Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and an underweight position in the information technology sector weighed on the fund's relative performance.

  • Stock selection within both the industrials and materials sectors also hindered relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class A over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/a for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

GNDA-ANN

MFS^® Global New Discovery Fund

Class B-GLNBX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class B shares of the MFS Global New Discovery Fund (fund) provided a total return of 5.79%, at net asset value. This compares with a return of 22.35% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 19.70%.

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and underweight positions in both the real estate and financials sectors aided relative performance.

  • The fund's avoidance of the utilities sector also benefited relative returns.

• Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and an underweight position in the information technology sector weighed on the fund's relative performance.

  • Stock selection within both the industrials and materials sectors also hindered relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class B over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. 

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods.

CDSC – Contingent Deferred Sales Charge.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/b for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

GNDB-ANN

MFS^® Global New Discovery Fund

Class C-GLNCX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class C shares of the MFS Global New Discovery Fund (fund) provided a total return of 5.79%, at net asset value. This compares with a return of 22.35% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 19.70%.

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and underweight positions in both the real estate and financials sectors aided relative performance.

  • The fund's avoidance of the utilities sector also benefited relative returns.

• Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and an underweight position in the information technology sector weighed on the fund's relative performance.

  • Stock selection within both the industrials and materials sectors also hindered relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class C over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. 

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods.

CDSC – Contingent Deferred Sales Charge.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/c for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

GNDC-ANN

MFS^® Global New Discovery Fund

Class I-GLNIX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class I shares of the MFS Global New Discovery Fund (fund) provided a total return of 6.86%, at net asset value. This compares with a return of 22.35% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 19.70%.

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and underweight positions in both the real estate and financials sectors aided relative performance.

  • The fund's avoidance of the utilities sector also benefited relative returns.

• Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and an underweight position in the information technology sector weighed on the fund's relative performance.

  • Stock selection within both the industrials and materials sectors also hindered relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class I over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. 

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/i for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

GNDI-ANN

MFS^® Global New Discovery Fund

Class R1-GLNJX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class R1 shares of the MFS Global New Discovery Fund (fund) provided a total return of 5.84%, at net asset value. This compares with a return of 22.35% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 19.70%.

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and underweight positions in both the real estate and financials sectors aided relative performance.

  • The fund's avoidance of the utilities sector also benefited relative returns.

• Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and an underweight position in the information technology sector weighed on the fund's relative performance.

  • Stock selection within both the industrials and materials sectors also hindered relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class R1 over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. 

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods.

If the 1-year without sales charge return included adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles, the return would be 5.80%.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/r1 for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

GNDR1-ANN

MFS^® Global New Discovery Fund

Class R2-GLNKX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class R2 shares of the MFS Global New Discovery Fund (fund) provided a total return of 6.34%, at net asset value. This compares with a return of 22.35% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 19.70%.

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and underweight positions in both the real estate and financials sectors aided relative performance.

  • The fund's avoidance of the utilities sector also benefited relative returns.

• Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and an underweight position in the information technology sector weighed on the fund's relative performance.

  • Stock selection within both the industrials and materials sectors also hindered relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class R2 over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. 

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/r2 for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

GNDR2-ANN

MFS^® Global New Discovery Fund

Class R3-GLNLX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class R3 shares of the MFS Global New Discovery Fund (fund) provided a total return of 6.60%, at net asset value. This compares with a return of 22.35% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 19.70%.

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and underweight positions in both the real estate and financials sectors aided relative performance.

  • The fund's avoidance of the utilities sector also benefited relative returns.

• Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and an underweight position in the information technology sector weighed on the fund's relative performance.

  • Stock selection within both the industrials and materials sectors also hindered relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class R3 over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. 

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods.

If the 1-year without sales charge return included adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles, the return would be 6.56%.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/r3 for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

GNDR3-ANN

MFS^® Global New Discovery Fund

Class R4-GLNMX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class R4 shares of the MFS Global New Discovery Fund (fund) provided a total return of 6.89%, at net asset value. This compares with a return of 22.35% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 19.70%.

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and underweight positions in both the real estate and financials sectors aided relative performance.

  • The fund's avoidance of the utilities sector also benefited relative returns.

• Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and an underweight position in the information technology sector weighed on the fund's relative performance.

  • Stock selection within both the industrials and materials sectors also hindered relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class R4 over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. 

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods.

If the 1-year without sales charge return included adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles, the return would be 6.85%.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/r4 for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

GNDR4-ANN

MFS^® Global New Discovery Fund

Class R6-GLNNX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Global New Discovery Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class R6 shares of the MFS Global New Discovery Fund (fund) provided a total return of 6.96%, at net asset value. This compares with a return of 22.35% for the fund’s benchmark, the MSCI All Country World Index (net div). The fund's other benchmark, the MSCI All Country World Small Mid Cap Index (net div), generated a return of 19.70%.

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and underweight positions in both the real estate and financials sectors aided relative performance.

  • The fund's avoidance of the utilities sector also benefited relative returns.

• Top detractors from performance relative to the MSCI All Country World Small Mid Cap Index:

  • Stock selection and an underweight position in the information technology sector weighed on the fund's relative performance.

  • Stock selection within both the industrials and materials sectors also hindered relative results.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class R6 over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. 

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/r6 for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Top ten holdings

Issuer country weightings

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

GNDR6-ANN

MFS^® U.S. Government
Money Market Fund

MCMXX

Annual Shareholder Report

This annual shareholder report contains important information about MFS U.S. Government Money Market Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

FUND EXPENSES

What were the fund costs for the last year?

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Composition including fixed income credit
quality

Maturity breakdown

Ratings are assigned to portfolio securities utilizing ratings from Moody’s, Fitch, and Standard & Poor’s rating agencies and applying the following hierarchy: If all three agencies provide a rating, the middle rating (after dropping the highest and lowest ratings) is assigned; if two of the three agencies rate a security, the lower of the two is assigned. Ratings are shown in the S&P scale. All ratings are subject to change. The fund did not hold unrated securities. The fund is not rated by these agencies.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, and statement of additional information online at funds.mfs.com. The fund’s holdings as of each month end and the fund’s Form N-MFP reports are available online at mfs.com/mm-reports. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

MCM-ANN

MFS^® Mid Cap Growth Fund

Class A-OTCAX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Mid Cap Growth Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class A shares of the MFS Mid Cap Growth Fund (fund) provided a total return of ‑1.50%, at net asset value. This compares with a return of 20.10% for the fund’s benchmark, the Russell 3000^® Index. The fund's other benchmark, the Russell Midcap^® Growth Index, generated a return of ‑1.16%.

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the Russell Midcap^® Growth Index:

  • Stock selection within the health care sector strengthened the fund's relative performance.

• Top detractors from performance relative to the Russell Midcap^® Growth Index:

  • Stock selection within both the energy and materials sectors held back relative performance.

  • The fund's underweight position in the industrials sector also weakened relative returns.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class A over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. This graph includes the deduction of the maximum applicable sales charge.

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/a for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Equity sectors

Top ten holdings

MFS uses the Global Industry Classification Standard (GICS^®) for sector/industry reporting. MFS has applied its own internal sector/industry classification methodology for equity securities and non-equity securities that are unclassified by GICS.

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective June 10, 2026, the MFS Mid Cap Growth Fund revised its existing policy to invest at least 80% of its net assets in issuers with medium market capitalizations to reflect that the Fund will invest at least 80% of its net assets in growth companies with medium market capitalizations and expanded on the factors used to define issuers with medium market capitalizations and growth companies.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

OTCA-ANN

MFS^® Mid Cap Growth Fund

Class B-OTCBX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Mid Cap Growth Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class B shares of the MFS Mid Cap Growth Fund (fund) provided a total return of ‑2.22%, at net asset value. This compares with a return of 20.10% for the fund’s benchmark, the Russell 3000^® Index. The fund's other benchmark, the Russell Midcap^® Growth Index, generated a return of ‑1.16%.

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the Russell Midcap^® Growth Index:

  • Stock selection within the health care sector strengthened the fund's relative performance.

• Top detractors from performance relative to the Russell Midcap^® Growth Index:

  • Stock selection within both the energy and materials sectors held back relative performance.

  • The fund's underweight position in the industrials sector also weakened relative returns.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class B over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. 

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods.

CDSC – Contingent Deferred Sales Charge.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/b for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Equity sectors

Top ten holdings

MFS uses the Global Industry Classification Standard (GICS^®) for sector/industry reporting. MFS has applied its own internal sector/industry classification methodology for equity securities and non-equity securities that are unclassified by GICS.

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective June 10, 2026, the MFS Mid Cap Growth Fund revised its existing policy to invest at least 80% of its net assets in issuers with medium market capitalizations to reflect that the Fund will invest at least 80% of its net assets in growth companies with medium market capitalizations and expanded on the factors used to define issuers with medium market capitalizations and growth companies.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

OTCB-ANN

MFS^® Mid Cap Growth Fund

Class C-OTCCX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Mid Cap Growth Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class C shares of the MFS Mid Cap Growth Fund (fund) provided a total return of ‑2.26%, at net asset value. This compares with a return of 20.10% for the fund’s benchmark, the Russell 3000^® Index. The fund's other benchmark, the Russell Midcap^® Growth Index, generated a return of ‑1.16%.

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the Russell Midcap^® Growth Index:

  • Stock selection within the health care sector strengthened the fund's relative performance.

• Top detractors from performance relative to the Russell Midcap^® Growth Index:

  • Stock selection within both the energy and materials sectors held back relative performance.

  • The fund's underweight position in the industrials sector also weakened relative returns.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class C over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. 

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods.

CDSC – Contingent Deferred Sales Charge.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/c for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Equity sectors

Top ten holdings

MFS uses the Global Industry Classification Standard (GICS^®) for sector/industry reporting. MFS has applied its own internal sector/industry classification methodology for equity securities and non-equity securities that are unclassified by GICS.

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective June 10, 2026, the MFS Mid Cap Growth Fund revised its existing policy to invest at least 80% of its net assets in issuers with medium market capitalizations to reflect that the Fund will invest at least 80% of its net assets in growth companies with medium market capitalizations and expanded on the factors used to define issuers with medium market capitalizations and growth companies.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.

IMPORTANT NOTICE REGARDING DELIVERY OF SHAREHOLDER MATERIALS

The fund produces financial annual and semiannual reports and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund's annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund's records. However, any shareholder may contact the fund at 1-800-225-2606 or the shareholder's financial intermediary to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

OTCC-ANN

MFS^® Mid Cap Growth Fund

Class I-OTCIX

Annual Shareholder Report

This annual shareholder report contains important information about MFS Mid Cap Growth Fund for the period of September 1, 2025 to August 31, 2026. You can find additional information about the fund at funds.mfs.com. You can also request this information by contacting us at 1‑800‑225‑2606 or by sending an e-mail request to [email protected].

This report describes certain changes to the Fund that occurred during the reporting period.

FUND EXPENSES

What were the fund costs for the last year?

MANAGEMENT'S DISCUSSION OF FUND PERFORMANCE

• For the twelve months ended August 31, 2026, Class I shares of the MFS Mid Cap Growth Fund (fund) provided a total return of ‑1.23%, at net asset value. This compares with a return of 20.10% for the fund’s benchmark, the Russell 3000^® Index. The fund's other benchmark, the Russell Midcap^® Growth Index, generated a return of ‑1.16%.

• Global equity markets reached record levels during the period, withstanding considerable volatility amid tariffs, geopolitical conflict and high levels of uncertainty. A new geopolitical event distressed markets as US and Israeli forces launched strikes against Iran, disrupting Mideast oil and natural gas exports. During the period, renewed focus on defense and infrastructure spending brightened the economic outlook in Europe while in Japan, the election of a pro-growth prime minister sent stocks to new highs. Optimism over artificial intelligence remained high globally. 

• While the US Supreme Court struck down part of the Trump administration’s tariff strategy, the administration began deploying other authorities to largely replace the ones that were ruled unconstitutional. 

• Higher energy prices and the lingering impact from tariffs kept inflation elevated in the US, prompting the Federal Reserve to end its easing cycle. Both the European Central Bank and the Bank of Japan raised rates toward the end of the period. 

• In fixed income markets, previously range-bound global bond yields climbed following the February 2026 onset of the conflict in the Middle East and as investors appeared to price in greater fiscal and monetary uncertainty. During the Iran war, global credit spreads widened modestly before stabilizing near pre-conflict levels, supported by strong demand and resilient underlying fundamentals. Similarly, US rate volatility (as measured by the Merrill Lynch Option Volatility Estimate (MOVE) Index) rose from intra-period lows before retracting back near prior levels.

• Top contributors to performance relative to the Russell Midcap^® Growth Index:

  • Stock selection within the health care sector strengthened the fund's relative performance.

• Top detractors from performance relative to the Russell Midcap^® Growth Index:

  • Stock selection within both the energy and materials sectors held back relative performance.

  • The fund's underweight position in the industrials sector also weakened relative returns.

FUND PERFORMANCE

The fund’s past performance is not a good predictor of the fund’s future performance. The graph and table below do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The graph and table below assume reinvestment of dividends and capital gain distributions.

Growth of a Hypothetical $10,000 Investment

This graph shows the performance of a hypothetical $10,000 investment in Class I over a ten year period or since inception, if shorter, in comparison to (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests. 

Average Annual Total Returns through 8/31/26

This table shows the average annual total returns of the class of shares noted for the periods shown, both with (if any) and without sales charges. It also shows the average annual total returns of (i) a broad measure of market performance and (ii) an additional index that MFS believes more closely reflects the market segments in which the fund invests, over the same periods.

Notes to Fund Performance

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

Visit mfs.com/perf/i for more recent performance information.

FUND STATISTICS AS OF 8/31/26

# Includes the effect of any management fee waivers, if applicable.

Where the fund holds derivatives, they are not included in the total number of portfolio holdings.

PORTFOLIO COMPOSITION (BASED ON TOTAL INVESTMENTS AS OF 8/31/26)

Portfolio structure

Equity sectors

Top ten holdings

MFS uses the Global Industry Classification Standard (GICS^®) for sector/industry reporting. MFS has applied its own internal sector/industry classification methodology for equity securities and non-equity securities that are unclassified by GICS.

MATERIAL FUND CHANGES

This is a summary of certain changes to the fund since September 1, 2025. For more complete information, you may review the fund's prospectus as amended, which is available at funds.mfs.com or upon request at 1‑800‑225‑2606.

Effective June 10, 2026, the MFS Mid Cap Growth Fund revised its existing policy to invest at least 80% of its net assets in issuers with medium market capitalizations to reflect that the Fund will invest at least 80% of its net assets in growth companies with medium market capitalizations and expanded on the factors used to define issuers with medium market capitalizations and growth companies.

ADDITIONAL INFORMATION

You can find the fund’s summary prospectus, prospectus, most recent annual and semiannual reports, financial information, portfolio holdings, and statement of additional information online at funds.mfs.com. Proxy voting information is available without charge by calling 1‑800‑225‑2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s website at http://www.sec.gov.