New Mountain Finance Corp (0001496099) (Filer)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of Earliest Event Reported): November 2, 2026

New Mountain Finance Corporation

(Exact name of registrant as specified in its charter)

1633 Broadway, 48th Floor, New York, NY 10019

(Address of principal executive offices)(zip code)

Registrant’s telephone number, including area code (212) 720-0300

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

On November 2, 2026, New Mountain Finance Corporation (“NMFC” or the “Company”) issued a press release announcing financial results for its quarter ended September 30, 2026. The press release is included as Exhibit 99.1 hereto and incorporated herein by reference.

The information disclosed under this Item 2.02, including Exhibit 99.1 hereto, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, (the “Exchange Act”) or otherwise subject to the liabilities of that section. The information provided herein shall not be deemed incorporated by reference into any filing made under the Securities Act of 1933, as amended, (the “Securities Act”) except as expressly set forth by specific reference in such filing.

Item 7.01.    Regulation FD Disclosure

    On November 2, 2026, NMFC issued a press release, included herewith as Exhibit 99.1, announcing the declaration of a fourth quarter 2026 distribution of $0.25 per share, payable on December 31, 2026 to holders of record as of December 17, 2026. Additionally, on November 2, 2026, NMFC made available on its website, http://www.newmountainfinance.com, a supplemental investor presentation with respect to the earnings release.

The information disclosed under this Item 7.01, including Exhibit 99.1 hereto, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Exchange Act, or otherwise subject to the liabilities of that section. The information provided herein shall not be deemed incorporated by reference into any filing made under the Securities Act, except as expressly set forth by specific reference in such filing.

d) Exhibits.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this Current Report on Form 8-K to be signed on its behalf by the undersigned hereunto duly authorized.