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): June 4, 2021

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)

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:

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 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR §240.12b-2).

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 June 4, 2021, New Mountain Finance Corporation (the “Company”) entered into the Amended and Restated Senior Secured Revolving Credit Agreement (the “Amended and Restated Credit Agreement”), amending and restating the Company’s existing senior secured revolving credit facility dated June 4, 2014, as previously amended, by and among Goldman Sachs Bank USA as the Administrative Agent and Issuing Bank, and Goldman Sachs Bank USA, Morgan Stanley Bank, N.A. and Stifel Bank & Trust as Lenders.  The Amended and Restated Credit Agreement, among other things, (i) extends the Commitment Termination Date from June 4, 2021 to June 4, 2025, (ii) extends the Final Maturity Date from June 4, 2022 to June 4, 2026, (iii) decreases the applicable margin from 1.50% to 1.10% per annum for any ABR loan and from 2.50% to 2.10% for any Eurocurrency loan, (iv) updates the language and definitions which allow for the replacement of the LIBOR Rate (and the applicable rates for certain foreign currencies) upon the occurrence of certain events and (v) reduces the required minimum aggregate value of Portfolio Investments that must be Quoted Investments from 37.5% to 30.0% of the aggregate value of all Portfolio Investments.

In addition to the amendments described above, the Amended and Restated Credit Agreement increases the maximum amount to which the facility may be increased from $200 million to $275 million. As of the date of the Amended and Restated Credit Agreement, the amount of the total commitments under the facility remains $188.5 million, of which $75 million are U.S. dollar commitments and $113.5 million are multi-currency commitments.

The description above is only a summary of the material provisions of the Amended and Restated Credit Agreement and is qualified in its entirety by reference to the copy of the Amended and Restated Credit Agreement which is filed as Exhibit 10.1 to this current report on Form 8-K and is incorporated herein by reference thereto.

The disclosure set forth above under Item 1.01 is incorporated by reference herein.

Exhibit No.

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.