UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

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FORM 8-K

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CURRENT REPORT

Pursuant to section 13 or 15(d) of the
Securities Exchange Act of 1934

Date of Report (Date of Earliest Event Reported): September 21, 2015 (September 21, 2015)

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New Mountain Finance Corporation
(Exact name of registrant as specified in its charter)

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787 7^th Avenue, 48^th Floor, New York, NY 10019
(Address of principal executive offices)

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

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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:
⃞ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
⃞ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
⃞ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
⃞ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

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Set forth below is a preliminary estimate of New Mountain Finance Corporation’s (“NMFC”, “us”, “we”, “our”, or the “Company”) net asset value per share as of September 21, 2015 and a preliminary estimate of our adjusted net investment income per share range for the three months ended September 30, 2015. The following estimates are not a comprehensive statement of our financial condition or results for the period from December 31, 2014 through September 21, 2015.  We advise you that our actual results for the three and nine months ended September 30, 2015 may differ materially from these estimates, which are given only as of September 21, 2015, as a result of the completion of our financial closing procedures, final adjustments and other developments, including changes in interest rates or changes in the businesses to whom we have made loans, which may arise between now and the time that our financial results for the three and nine months ended September 30, 2015 are finalized. This information is inherently uncertain.

As of September 21, 2015, we currently expect that we will meet our adjusted net investment income per share estimate of between $0.33 and $0.35 for the three months ended September 30, 2015, which was previously announced on our quarterly earnings call held on August 6, 2015.

As of September 21, 2015, we estimate that our net asset value per share is approximately $13.78.

The preliminary financial estimates provided have been prepared by, and are the responsibility of, management. Neither Deloitte & Touche LLP, our independent registered public accounting firm, nor any other independent accountants, have audited, reviewed, compiled, or performed any procedures with respect to the accompanying preliminary financial data. Accordingly, Deloitte & Touche LLP does not express an opinion or any form of assurance with respect thereto and assumes no responsibility for, and disclaims any association with, this information.

The information disclosed under this Item 2.02 is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934 and shall not be deemed incorporated by reference into any filing made under the Securities Act of 1933, except as expressly set forth by specific reference in such filing.

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.