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

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of
the Securities Exchange Act of 1934 (Amendment No.  )

Filed by the Registrant ☒

Filed by a Party other than the Registrant  o

Check the appropriate box:

New Mountain Finance Corporation
787 Seventh Avenue, 48th Floor
New York, New York 10019

March 14,May 7, 2018

Dear Stockholder:

You are cordially invited to attend the 2018 AnnualSpecial Meeting of Stockholders (“AnnualSpecial Meeting”) of New Mountain Finance Corporation (“NMFC” or the “Company”) to be held on April 26,June 8, 2018 at 9:1:00 a.m.p.m., Eastern Time. You will be able to participate in the AnnualSpecial Meeting, vote and submit your questions via live webcast by visiting www.virtualshareholdermeeting.com/NMFC2018NMFC2018SM. Prior to the AnnualSpecial Meeting you will be able to vote electronically at www.proxyvote.com.

The notice of the AnnualSpecial Meeting and the proxy statement accompanying this letter provide an outline of the business to be conducted at the AnnualSpecial Meeting. At the AnnualSpecial Meeting the stockholders of NMFC will be asked to (i) elect two directorsapprove of the Company becoming subject to a minimum asset coverage ratio of at least 150%, permitting the Company to double its amounts of debt incurrence, pursuant to the board of directors of NMFC to serve for a term of three years, or until their respective successors are duly electedSmall Business Credit Availability Act; and qualify; (ii) ratify the appointment of Deloitte & Touche LLP as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2018 and (iii) to transact such other business that may properly come before the AnnualSpecial Meeting.

It is important that your shares be represented at the AnnualSpecial Meeting. If you are unable to participate in the AnnualSpecial Meeting during the scheduled time, I urge you to follow the instructions on the Notice of Internet Availability of Proxy Materials to vote your proxy on the Internet. I encourage you to vote via the Internet, as it saves us significant time and processing costs. However, on the Notice of Internet Availability of Proxy Materials, you will also find instructions on how to request a hard copy of the Proxy Statement and proxy card free of charge and you may vote your proxy by returning your proxy card to us after you request the hard copy materials.us. Your vote is important.

To vote or to submit your questions during the AnnualSpecial Meeting, please log on to www.virtualshareholdermeeting.com/NMFC2018NMFC2018SM. You will need to enter the 12-digit16-digit control number on your notice of the AnnualSpecial Meeting. Your vote is important to us.

	Sincerely yours,
	Robert A. Hamwee Chief Executive Officer

Important Notice Regarding the Availability of Proxy Materials for the
Special Meeting of Stockholders to Be Held on June 8, 2018.

Our proxy statement relating to the Special Meeting is available on the Internet at www.virtualshareholdermeeting.com/NMFC2018SM.

The following information applicable to the Special Meeting may be found in the proxy statement and accompanying proxy card:

New Mountain Finance Corporation
787 Seventh Avenue, 48th Floor
New York, New York 10019

NOTICE OF ANNUALSPECIAL MEETING OF STOCKHOLDERS
AND INTERNET AVAILABILITY OF PROXY MATERIALS
STOCKHOLDERS TO BE HELD ON APRIL 26,JUNE 8, 2018

To the Stockholders of New Mountain Finance Corporation:

A meeting (the “Annual“Special Meeting”) of stockholders of New Mountain Finance Corporation (“NMFC” or the “Company”) will be held on April 26,June 8, 2018 at 9:1:00 a.m.p.m., Eastern Time. We are very pleased that this year’s Annualthe Special Meeting will be a completely virtual meeting of stockholders, which will be conducted via live webcast. It is important to note that shareholders have the same rights and opportunities by participating in a virtual meeting, as they would if attending an in-person meeting. You can participate in the AnnualSpecial Meeting, vote and submit your questions during the AnnualSpecial Meeting by visiting www.virtualshareholdermeeting.com/NMFC2018NMFC2018SM. You must have your 12- Digit16-Digit Control Number in order to access the AnnualSpecial Meeting. The AnnualSpecial Meeting will be held for the following purposes:

You have the right to receive notice of, and to vote at, the AnnualSpecial Meeting if you were a stockholder of record at the close of business on March 1,April 16, 2018. NMFC is furnishing the Proxy Statement and proxy card to its stockholders on the Internet, rather than mailing printed copies of those materials to each stockholder. If you received a Notice of Internet Availability of Proxy Materials by mail, you will not receive a printed copy of the Proxy Statement and proxy card unless you request them. Instead, the Notice of Internet Availability of Proxy Materials will instruct you as to how you may access and review the Proxy Statement, and vote your proxy, on the Internet.

Your vote is extremely important to us. IfWhether or not you are unableexpect to attend the AnnualSpecial Meeting, we encourageand whatever the number of shares you to vote your proxy on the Internet by following the instructions provided on the Notice of Internet Availability of Proxy Materials. You may also request from us, free of charge, hard copies of the Proxy Statement and proxy card for the Company by followingown, please follow the instructions on the Notice ofenclosed proxy card to vote your shares via the Internet Availability of Proxy Materials.or telephone, or by signing, dating and returning the proxy card in the postage-paid envelope provided. In the event there are not sufficient votes for a quorum or to approve NMFC’s proposals at the time of the AnnualSpecial Meeting, the AnnualSpecial Meeting may be adjourned in order to permit further solicitation of proxies by NMFC.

	By Order of the Board of Directors,
	Karrie J. Jerry Corporate Secretary

New York, New York
March 14,May 7, 2018

This is an important meeting. To ensure proper representation at the AnnualSpecial Meeting, please follow the instructions on the Notice of Internet Availability of Proxy Materials to vote your proxy via the Internet or request, complete, sign, date and return athe proxy card.card in the enclosed, self-addressed envelope, vote your shares by telephone, or vote via the Internet. Even if you vote your shares prior to the AnnualSpecial Meeting, you still may attend the AnnualSpecial Meeting and vote your shares via the Internet.shares.

New Mountain Finance Corporation
787 Seventh Avenue, 48th Floor
New York, New York 10019

PROXY STATEMENT

2018 AnnualSpecial Meeting
of Stockholders of
New Mountain Finance Corporation

This Proxy Statement is furnished in connection with the solicitation of proxies by the board of directors of New Mountain Finance Corporation (“NMFC”, the “Company”, “we”, “us” or “our”) for use at the NMFC 2018 AnnualSpecial Meeting (the “Annual“Special Meeting”) to be held on April 26,June 8, 2018, at 9:1:00 a.m.p.m., Eastern Time. You can virtually attend the AnnualSpecial Meeting online, vote your shares electronically and submit questions during the AnnualSpecial Meeting by visiting www.virtualshareholdermeeting.com/NMFC2018NMFC2018SM, and at any postponements or adjournments thereof. You will need to enter the 12-digit16-digit control number on your notice of the AnnualSpecial Meeting. It is important to note that shareholders have the same rights and opportunitesopportunities by participating in a virtual meeting, as they would if attending an in-person meeting. This Proxy Statement isand the accompanying proxy card are first being providedsent to theour stockholders of NMFC via the Internetrecord on or about March 13, 2018. In addition, a Notice of Annual Meeting and a Notice of Internet Availability of Proxy Materials are being sent to stockholders of record of NMFC on or about March 14,May 9, 2018.

We encourage you to vote your shares of NMFC’s stock either by voting via the Internet while virtually attending the AnnualSpecial Meeting, by telephone, or by granting a proxy (i.e.,authorizing someone to vote your shares). Shares represented by duly executed proxies will be voted in accordance with your instructions. If you give no instructions on the proxy card, the shares covered by the proxy card will be voted “FOR” the matters listed in this Proxy Statement.

If you are a stockholder “of record” (i.e.,you hold shares directly in your name), you may revoke a proxy at any time before it is exercised by notifying the proxy tabulator, Broadridge Shareholder Services, in writing, by submitting a properly executed, later-dated proxy, or by voting virtually at the AnnualSpecial Meeting. Please send your notification to Proxy Services, P.O. Box 9175, Farmingdale, New York 11735-9852, and submit a properly executed, later-dated proxy or vote virtually at the AnnualSpecial Meeting. Any stockholder of record attending the AnnualSpecial Meeting may vote virtually whether or not he or she has previously voted his or her shares. If your shares are held for your account by a broker, bank or other institution or nominee (“Broker Securities”), you may vote such securities at the AnnualSpecial Meeting only if you obtain proper written authority from your institution or nominee and present it at the AnnualSpecial Meeting. All of our directors are encouraged to attend the AnnualSpecial Meeting. Stockholders have no dissenters’ or appraisal rights in connection with any of the proposals described herein.

Stockholders of record may also vote either via the Internet or by telephone. Specific instructions to be followed by stockholders of record interested in voting via the Internet or the telephone are shown on the enclosed proxy card. The Internet and telephone voting procedures are designed to authenticate the voter’s identity and to allow stockholders to vote their shares and confirm that their instructions have been properly recorded.

TABLE OF CONTENTS

Purpose of AnnualSpecial Meeting

At the AnnualSpecial Meeting:

Shares

Stockholders of NMFC may vote their shares, virtually or by proxy, at the AnnualSpecial Meeting only if such stockholders were stockholders of record at the close of business on March 1,April 16, 2018 (the “Record Date”). On the Record Date, there were 75,935,093 shares of NMFC’s common stock outstanding. Each share of NMFC’s common stock is entitled to one vote.

Quorum
Required

A quorum of NMFC’s stockholders must be present at the AnnualSpecial Meeting for any business to be conducted. The presence at the AnnualSpecial Meeting, online or by proxy, of the holders of a majority of the shares of NMFC common stock outstanding on the Record Date will constitute a quorum. Abstentions will be treated as shares present for quorum purposes. Broker Securities for which the nominee has not received voting instructions from the record holder and does not have discretionary authority to vote the shares on certain proposals (which are considered “Broker Non-Votes” with respect to such proposals) will be treated as shares present for quorum purposes.

If a quorum is not present at the AnnualSpecial Meeting, the stockholders who are represented may adjourn the AnnualSpecial Meeting until a quorum is present. The persons named as proxies will vote those proxies for such adjournment, unless marked to be voted against any proposal for which an adjournment is sought, to permit the further solicitation of proxies.

Vote
Required

ElectionApproval of Directors.the Company becoming subject to a minimum asset coverage ratio of at least 150%, permitting A nominee for director shall be electedthe Company to double its amount of debt incurrence, pursuant to the board of directors of NMFC if the votes cast for such nominee’s election exceed the votes cast against such nominee’s election. If you vote “Withhold Authority” with respect to a nominee, your shares will not be voted with respect to the person indicated. Abstentions and Broker Non-Votes will not be included in determining the number of votes cast and, as a result, will have no effect on this proposal.

Ratification of Independent Registered Public Accounting Firm.SBCA. The affirmative vote of a majority of the votes cast at the Annual Meeting or by proxyfor this proposal is required to ratifyauthorize the appointmentCompany to be subject to a minimum asset coverage ratio of Deloitte & Touche LLP to serve as the Company’s independent registered public accounting firm for the fiscal year ended December 31, 2018.at least 150%. Abstentions and Broker Non-Votes will not be included in determining the number of votes cast and, as a result, will have no effect on this proposal. Because brokers will have discretionary authority to vote for the ratification of the appointment of the Company’s independent registered public accounting firm in the event that they do not receive voting instructions from the beneficial owner of the shares, your broker will be permitted to vote your shares for this proposal. If you give no instructions on the proxy card, the shares covered by the proxy card will be voted FOR the ratification of appointment of Deloitte & Touche LLP to serve as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2018.

Additional Solicitation.If there are not enough votes to approve any proposals at the AnnualSpecial Meeting, the stockholders who are represented may adjourn the AnnualSpecial Meeting to permit the further solicitation of proxies. The persons named as proxies will vote those proxies for such adjournment, unless marked to be voted against the proposal for which an adjournment is sought, to permit the further solicitation of proxies.

Also, a vote may be taken on one or more of the proposals in this Proxy Statement prior to any such adjournment if there are sufficient votes for approval thereof.

In addition to the solicitation of proxies by the use of the mail, proxies may be solicited in person and by telephone or facsimile transmission by directors, officers or employees of NMFC, NMFC’s investment adviser, New Mountain Finance Advisers BDC, L.L.C. (the “Investment Adviser”), or NMFC’s administrator, New Mountain Finance Administration, L.L.C. (the “Administrator”), without special compensation therefor. The Company has also retained Broadridge Financial Solutions, Inc. to assist in the solicitation of proxies for the Special Meeting for a fee of approximately $4,500, plus reimbursement of certain out-of-pocket expenses.

Stockholders may also provide their voting instructions by telephone or through the Internet. These options require stockholders to input the Control Number which is located on each proxy card. After inputting this number, stockholders will be prompted to provide their voting instructions. Stockholders will have an opportunity to review their voting instructions and make any necessary changes before submitting their voting instructions and terminating their telephone call or Internet link. Stockholders who vote via the Internet, in addition to confirming their voting instructions prior to submission, will also receive an e-mail confirming their instructions upon request.

Any proxy given pursuant to this solicitation may be revoked by notice from the person giving the proxy at any time before it is exercised. Any such notice of revocation should be provided in writing and signed by the stockholders in the same manner as the proxy being revoked and delivered to NMFC’s proxy tabulator.

The principal business address of both the Investment Adviser and the Administrator is 787 Seventh Avenue, 48th Floor, New York, New York 10019.

Control Persons and Principal
Stockholders

The following table sets forth information with respect to the beneficial ownership of NMFC’s common stock as of the Record Date by:

Beneficial ownership has been determined in accordance with Rule 13d-3 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”) and includes voting or investment power (including the power to dispose) with respect to the securities and assumes no other purchases or sales of securities since the most recently available Securities and Exchange Commission (“SEC”) filings. This assumption has been made under the rules and regulations of the SEC and does not reflect any knowledge that NMFC has with respect to the present intent of the beneficial owners of the securities listed in the table below.

Percentage of beneficial ownership below takes into account 75,935,093 shares of common stock of NMFC outstanding as of the Record Date. Unless otherwise indicated, the address for each listed holder is c/o New Mountain Finance Corporation, 787 Seventh Avenue, 48th Floor, New York, New York 10019.

PROPOSAL

PROPOSALS
PROPOSAL I: PROPOSAL 1: ELECTIONAPPROVAL OF DIRECTORSTHE COMPANY BECOMING SUBJECT TO A MINIMUM ASSET COVERAGE RATIO OF AT LEAST 150%, PERMITTING THE COMPANY TO DOUBLE ITS AMOUNT OF DEBT INCURRENCE, PURSUANT TO THE SMALL BUSINESS CREDIT AVAILABILITY ACT

PursuantThe Company is a closed-end investment company that has elected to NMFC’s governing documents,be regulated as a business development company (“BDC”) under the Investment Company Act of 1940, as amended (the “1940 Act”). As a BDC, we are required to meet a minimum asset coverage ratio, reflecting the value of our total assets to our total senior securities, which include all of our borrowings and any preferred stock we may issue in the future, under the 1940 Act. Prior to March 23, 2018, Section 61(a) of the 1940 Act (which incorporates the requirements of Sections 18(a)(1) and 18(a)(2) of the 1940 Act) did not permit a BDC to issue senior securities unless, at the time of issuance, such BDC had an asset coverage ratio of at least 200% taking into account such issuance of senior securities (the “Asset Coverage Ratio”). However, on March 23, 2018, the Small Business Credit Availability Act (the “SBCA”) was signed into law and permits BDCs to be subject to an Asset Coverage Ratio of at least 150% (the “150% Asset Coverage Ratio”), if certain conditions are satisfied as set forth in the SBCA.

Prior to the enactment of the SBCA, generally, for every $1.00 of debt incurred or in senior securities issued, a BDC was required to have at least $2.00 of assets immediately following such incurrence or issuance. For those BDCs that satisfy the SBCA’s disclosure and approval requirements, the minimum asset coverage ratio is reduced such that for every $1.00 of debt incurred or in senior securities issued, a BDC must now have at least $1.50 of assets. This reduction in the Asset Coverage Ratio doubles the amount of debt that BDCs may incur.

The SBCA provides that in order for a BDC whose common stock is traded on a national securities exchange to be subject to the 150% Asset Coverage Ratio, the BDC must obtain either: (i) approval of the required majority of its non-interested directors who have no financial interest in the proposal of the 150% Asset Coverage Ratio, which would become effective one (1) year after the date of such approval, or (ii) stockholder approval (of more than 50% of the votes cast for the proposal) of the 150% Asset Coverage Ratio, which would become effective on the first day after the date of such stockholder approval. BDCs must provide stockholders with timely notice of such approvals and must make periodic reports of the aggregate outstanding principal amounts of senior securities issued by BDC and the asset coverage percentage as of the most recent financial statements included in that filing, the effective date of the approval of the modified asset coverage requirements, and the principal risk factors associated with the senior securities, to the extent incurred by the BDC.

On April 12, 2018, our board of directors, of NMFC is divided into three classes. Directors are elected forincluding a staggered term of three years each, with a term of officemajority of the three classes ofnon-interested directors expiring each year. Each directorwho have no financial interest in this proposal, approved the 150% Asset Coverage Ratio, which will hold office for the term to which he or she is elected or until his or her successor is duly elected and qualifies.automatically become effective on April 12, 2019.

Messrs. David Ogens and Adam B. Weinstein have each been nominated for election for a three year term expiring in 2021 to theIn addition, on April 12, 2018, our board of directors of NMFC, have indicated their willingness to serve if elected and have consented to be named as nominees. Messrs. Ogens and Weinstein have not been proposed for election pursuant to any agreement or understanding between each of Messrs. Ogens and Weinstein and NMFC or any other person or entity.

A stockholder can vote for or withhold his or her vote fromdetermined that this proposal is in the nominees. In the absence of instructions to the contrary, it is the intentionbest interests of the persons named as proxies toCompany and its stockholders, and is recommending that the Company’s stockholders vote such proxy “FOR” the election of eachin favor of the nominees named below.proposal to reduce the Company’s Asset Coverage Ratio requirement to at least 150% for purposes of Sections 18(a)(1) and 18(a)(2) of the 1940 Act. If a nominee should decline orthis proposal is approved by stockholders at the Meeting, the Company would become subject to an Asset Coverage Ratio of at least 150% the day after the Meeting instead of on April 12, 2019. The Board of Directors values the opinions of our stockholders and will reconvene to reconsider its approval of the modified asset coverage requirements if this proposal is not approved by stockholders. There can be unable to serve as a director, it is intendedno assurance that the proxy will vote for the election of such person as is nominated by the board of directors as a replacement. The board of directors has no reason to believe that the persons named below will be unable or unwilling to serve.

THE BOARD OF DIRECTORS RECOMMENDS THAT YOU VOTE “FOR” THE ELECTION OF THE NOMINEES NAMED IN THIS PROXY STATEMENT.

Information about the Nominees and Directors

As described below under “Committees of the Board of Directors—NominatingDirectors would rescind its approval if this proposal is not approved by stockholders. If this proposal is not approved by stockholders and Corporate Governance Committee”, the boardBoard of directorsDirectors does not rescind its approval, we will be subject to the 150% Asset Coverage Ratio beginning April 12, 2019.

If this proposal is approved, this reduction in the required minimum Asset Coverage Ratio will increase the amount of NMFC has identified certain desired attributes for director nominees. Eachdebt that we are permitted to incur; as a result, we may incur additional indebtedness in the future, and therefore, the risk of an investment in us may increase. See “—Risks Related to the Approval of the directors and the director nominees have demonstrated high character and integrity, superior credentials and recognition in his respective field and the relevant expertise and experience upon which to be able to offer advice and guidance to our management. Each of the directors and the director nominees also have sufficient time available to devote to the affairs of NMFC, are able to work with the other members of the board of directors and contribute to the success of NMFC and can represent the long-term interests of NMFC’s stockholders, as a whole. NMFC’s directors and the director nominees have been selected such that the board of directors represents a range of backgrounds and experiences.

Certain information, as of the Record Date, with respect to the nominees for election at the Annual Meeting, as well as each of the current directors, is set forth below, including their names, ages, a brief description of their recent business experience, including present occupations and employment, certain directorships that each person holds, the year in which each person became a director of NMFC, and a discussion of their particular experience, qualifications, attributes or skills that lead us to conclude, as of the Record Date, that such individual should serve as a director of NMFC, in light of its business and structure.

The business address of the director nominees, other directors and executive officers listed below is c/o New Mountain Finance Corporation, 787 Seventh Avenue, 48th Floor, New York, New York 10019.Proposal.”

Nominees for Directors
IllustrationsClass I Directors—Term Expiring 2021 of the Effect of Lowering the Required Asset Coverage Ratio

Mr. Ogens is not an “interested person”The following table sets forth the following additional information:

Mr. Ogens brings his experience in wealth managementIn evaluating the information presented below, it is important to recognize that the maximum amount of borrowings that could be incurred by us is presented for comparative and investment banking, including experience with debt issuances, as well as industry-specific expertise ininformational purposes only and such information is not a representation of the healthcare industryamount of borrowings that we intend to NMFC’s board of directors. This background positions Mr. Ogens wellincur or that would be available to serve as a director of NMFC.

Mr. Weinstein is an “interested person” of NMFC as defined in 1940 Act dueus to his position as Executive Vice President and Chief Administrative Officer of NMFC.be incurred.

Current Directors
Class II Directors—Term Expiring 2019

Mr. Hamwee is an “interested person” of NMFC as defined in the Investment Company Act of 1940, as amended (the “1940 Act”) due to his position as the Chief Executive Officer of NMFC.

Class III Directors—Term Expiring 2020

Mr. Klinskyminimum asset coverage ratio, by the net assets attributable to common stock as of December 31, 2017, which were $1,035.0 million. The maximum amount of borrowings that could be incurred by us is an “interested person”presented for comparative and informational purposes only and such information is not a representation of NMFC as defined in the 1940 Act dueamount of borrowings that we intend to his position as the Founder and Chief Executive Officer of New Mountain Capital, L.L.C. since its inception in 1999.incur or that would be available to us to be incurred.

From his experienceExample. The following example demonstrates the projected dollar amount of total cumulative expenses that would be incurred over various periods with respect to a hypothetical investment of $1,000 in our common stock, assuming (1) a 240.8% asset coverage ratio, which is our actual asset coverage ratio as an executive or director of publicDecember 31, 2017, and private companies andtotal net annual expenses, excluding incentive fees, of financial advisory and private equity companies, Mr. Klinsky brings broad financial advisory and investment management expertise2.43% of net assets attributable to the board of directors. Mr. Klinsky’s intimate knowledge of the business and operations of NMFC,common stock as the Founder and Chief Executive Officer of New Mountain Capital, L.L.C. and his experience as a board member or chairman of other publicly-held companies, positions him well to serve as the chairman of NMFC’s board of directors.

Mr. Wolfgruber is not an “interested person” of NMFC as definedset forth in the 1940 Act.

Mr. Wolfgruber brings experience in portfolio managementtable above; (2) a 200% asset coverage ratio requirement and his abilities as a chartered financial analyst to the board of directors of NMFC. This background positions Mr. Wolfgruber well to serve as a director of NMFC.total net annual expenses,

Mr. Arnold is not an “interested person”excluding incentive fees, of NMFC2.62% of net assets attributable to common stock as defined in the 1940 Act.

Mr. Arnold brings his vast experience in investment banking and energy focus to the board of directors of NMFC. This background positions Mr. Arnold well to serve as a director of NMFC.

Information about Executive Officers Who Are Not Directors

The following information, as of the Record Date, pertains to the executive officers who are not directors or nominees for election as directors of NMFC.

Director Independence

In accordance with rules of the NYSE, NMFC’s board of directors annually determines each director’s independence. We do not consider a director independent unless the board of directors has determined that he has no material relationship with us. We monitor the relationships of our directors and officers through a questionnaire each director and officer completes no less frequently than annually and updates periodically as information provided in the most recent questionnaire changes.

Our governance guidelines, which are available on NMFC’s website at www.newmountainfinance.com, require any director who has previously been determined to be independent to inform the chairman of the board of directors, the chairman of the nominating and corporate governance committee and the corporate secretary of any change in circumstance that may cause his status as an independent director to change. The board of directors limits membership on the audit committee, the valuation committee, the nominating and corporate governance committee and the compensation committee to independent directors. In order to evaluate the materiality of any such relationship, the board of directors uses the definition of director independence set forth in the corporate governance listing standards promulgatedtable above; and (3) a 150% asset coverage ratio requirement and total net annual expenses, excluding incentive fees, of 3.30% of net assets attributable to common stock as set forth in the table above. In calculating the following expense amounts, we have assumed that our borrowings and annual operating expenses would remain at the levels set forth in the table above. See Note 6 above for additional information regarding certain assumptions regarding our level of leverage.

The boardWe believe that if we are unable to incur additional leverage at a time when presented with attractive investment opportunities, and issuing equity capital is unavailable to us or disadvantageous, the Company’s ability to grow could be adversely affected when compared to business development companies that have received stockholder approval to be subject to the 150% Asset Coverage Ratio.

Considerations by the Board of directors has determined that eachDirectors

In reaching its recommendation to the stockholders of the directors and the director nominees are independent and has no relationship with us, except as a director and stockholder of NMFC, with the exception of Steven B. Klinsky, as a result of his positions as founder and chief executive officer of New Mountain Capital, L.L.C., Robert A. Hamwee, as a result of his position as chief executive officer of NMFC and Adam B. Weinstein, as a result of his positions as executive vice president and chief administrative officer of NMFC.

Board Leadership Structure

NMFC’s board of directors monitors and performs an oversight role with respectCompany to NMFC’s business and affairs, compliance with regulatory requirements and the services, expenses and performance of service providers to NMFC. Among other things, NMFC’s board of directors approves the appointment of the Administrator and officers, reviews and monitors the services and activities performed by the Administrator and officers and approves the engagement, and reviews the performance of, NMFC’s independent public accounting firm.

Under NMFC’s bylaws, NMFC’s board of directors may designate a chairman to preside over the meetings ofapprove this proposal, the board of directors and meetingsconsidered possible sources of the stockholders and to perform such other duties as may be assignedconflicts of interest due to the chairman byfollowing factors:

Risks Related to Approval of the Proposal Permitting the Company to Double Its Amount of Debt Incurrence

In addition to the risks identified in our annual report for the year ended December 31, 2017, stockholders should consider the following risks related to the approval of this proposal:

Because we have received board of directors’ approval, we may be subject to 150% Asset Coverage Ratio beginning on April 12, 2019 if this proposal is not approved.

As described above, the SBCA provides that in order for a BDC whose common stock is traded on a national securities exchange to be subject to 150% Asset Coverage Ratio, the BDC must obtain either: (i) approval of the required majority of its non-interested directors who have no financial interest in the best interestsproposal of NMFCthe 150% Asset Coverage Ratio, which would become effective one (1) year after the date of such approval, or (ii) stockholder approval (of more than 50% of the votes cast for the proposal) of the 150% Asset Coverage Ratio, which would become effective on the first day after the date of such stockholder approval. The Board of Directors values the opinions of our stockholders and will reconvene to reconsider its approval of the modified asset coverage requirements if this proposal is not approved by stockholders. There can be no assurance that the Board of Directors would rescind its approval if this proposal is not approved by stockholders. If this proposal is not approved by stockholders at such times.and the Board of Directors does not rescind its approval, we will be subject to the 150% Asset Coverage Ratio beginning April 12, 2019.

Mr. Klinsky currently serves asIncurring additional leverage could increase the chairmanrisk of NMFC’s boardinvesting in the Company.

Leverage magnifies the potential for loss on investments in our indebtedness and on invested equity capital. As we use leverage to partially finance our investments, you will experience increased risks of directors. Mr. Klinskyinvesting in our securities. If the value of our assets increases, then leveraging would cause the net asset value attributable to our common stock to increase more sharply than it would have had we not leveraged. Conversely, if the value of our assets decreases, leveraging would cause net asset value to decline more sharply than it otherwise would have had we not leveraged our business. Similarly, any increase in our income in excess of interest payable on the borrowed funds would cause our net investment income to increase more than it would without the leverage, while any decrease in our income would cause net investment income to decline more sharply than it would have had we not borrowed. Such a decline could negatively affect our ability to pay common stock dividends, scheduled debt payments or other payments related to our securities. If this proposal is an “interested person”approved, we will be permitted to increase our use of NMFC as defined in Section 2(a)(19) ofleverage beyond levels that were previously permitted by the 1940 Act because he iseffective the founder and chief executive officer of New Mountain Capital, L.L.C., serves onday after the investment committee of the Investment Adviser and is the managing member of the sole member of the Investment Adviser. NMFC believes that Mr. Klinsky’s history with New Mountain Capital, L.L.C., familiarity with our investment objectives and investment strategy, and extensive knowledge of the financial services industry and the investment valuation process in particular qualify him to serve as the chairman of NMFC’sMeeting. Because we have received board of directors. NMFC believes that,directors’ approval, if the proposal is not approved at present, they are best served through this leadership structure, as Mr. Klinsky’s relationship with the Investment Adviser and New Mountain Capital, L.L.C., provides an effective bridge and encourages an open dialogue between NMFC’s management and its boardMeeting, we will be subject to the 150% Asset Coverage Ratio beginning on April 4, 2019. If we incur such additional leverage, you will experience increased risks of directors, ensuring that all groups act with ainvesting in our common purpose.stock.

NMFC’s board of directors does not currently have a designated lead independent director. NMFC is aware ofWe borrow money, which could magnify the potential conflicts thatfor gain or loss on amounts invested in us and increase the risk of investing in us.

We borrow money as part of our business plan. Borrowings, also known as leverage, magnify the potential for gain or loss on invested equity capital and may, arise when a non-independent director is chairmanconsequently, increase the risk of the board of directors, but believes these potential conflicts are offset by its strong corporate governance policies. NMFC’s corporate governance policies include regular meetings of the independent directorsinvesting in executive session without the presence of interested directors and management over which the chairman of the audit committee presides, the establishment of audit, valuation, nominating and corporate governance and compensation committees comprised solely of independent directors and the appointment of a chief compliance officer, with whom the independent directors meet regularly without the presence of interested directors and other members of management, for administering NMFC’s compliance policies and procedures.

NMFC recognizes that different board leadership structures are appropriate for companies in different situations. NMFC intendsus. We expect to continue to re-examine its corporate governance policies on an ongoing basisuse leverage to ensure that they continue to meet NMFC’s needs.

Board of Directors’ Role In Risk Oversight

NMFC’s board of directors performs its risk oversight function primarilyfinance our investments, through (1) its four standing committees which report to the board of directors, each of which is comprised solely of independent directorssenior securities issued by banks and (2) active monitoring by NMFC’s chief compliance officer and its compliance policies and procedures.

NMFC’s audit committee, valuation committee, nominating and corporate governance committee and compensation committee assist NMFC’s board of directors in fulfilling its risk oversight responsibilities. The audit committee’s risk oversight responsibilities include overseeing NMFC’s accounting and financial reporting processes, NMFC’s systems of internal controls regarding finance and accounting, and audits of NMFC’s financial statements, including the independence of NMFC’s independent auditors. The valuation committee is responsible for making recommendations in accordance with the valuation policies and procedures adopted by NMFC’s board of directors, reviewing valuations and any reports of independent valuation firms, confirming thatother

valuationslenders. Lenders of these senior securities have fixed dollar claims on our assets that are madesuperior to claims of our common stockholders, and we would expect such lenders to seek recovery against our assets in accordance with the valuation policiesevent of NMFC’s boarda default. If the value of directors and reportingour assets decreases, leveraging would cause our net asset value to decline more sharply than it otherwise would have had it not leveraged. Similarly, any deficiencies or violations of such valuation policiesdecrease in our income would cause our net income to NMFC’s board of directors on at leastdecline more sharply than it would have had it not borrowed. Such a quarterly basis, and reviewing other matters that NMFC’s board of directors or the valuation committee deems appropriate. The nominating and corporate governance committee’s risk oversight responsibilities include selecting, researching and nominating directors for election by NMFC’s stockholders, developing and recommendingdecline could adversely affect our ability to the board of directors a set of corporate governance principles and overseeing the evaluation of the board of directors and NMFC’s management. The compensation committee is responsible for periodically reviewing director compensation and recommending any appropriate changes to NMFC’s board of directors. The compensation committee is also responsible for annually reviewing and recommending for approval to NMFC’s board of directors an investment advisory and management agreement and an administration agreement.make common stock distribution payments. In addition, although NMFC does not directly compensate its executive officers currently,because our investments may be illiquid, we may be unable to the extent that NMFC doesdispose of them or to do so at a favorable price in the future, the compensation committee would also be responsible for reviewingevent we need to do so if we are unable to refinance any indebtedness upon maturity and, evaluating their compensation and making recommendations to the board of directors regarding their compensation.

NMFC’s board of directors performs its risk oversight responsibilities with the assistance of the chief compliance officer. The board of directors quarterly reviews a written report from the chief compliance officer discussing the adequacy and effectiveness of NMFC’s compliance policies and procedures and its service providers. The chief compliance officer’s quarterly report addresses at a minimum:

In addition, the chief compliance officer meets separatelyrisks associated with investing in executive session with the independent directors at least once each year.our securities.

NMFC believes that its board of director’s role in risk oversight is effective, and appropriate given the extensive regulation to which it is subject as a business development company. NMFC is required to comply with certain regulatory requirements that control the levels of risk in NMFC’s business and operations. For example, NMFC’sOur ability to service any debt that we incur indebtedness is limited because its asset coverage must equal at least 200.0% immediately after it incurs indebtedness. On November 5, 2014, the Company received exemptive relief from the SEC to permit the Company to exclude the SBA-guaranteed debentures of New Mountain Finance SBIC, L.P. and any other future SBIC subsidiaries, including New Mountain Finance SBIC II, L.P., from the Company’s 200.0% asset coverage test under the 1940 Act. As such, the Company’s ratio of total consolidated assets to outstanding indebtedness may be less than 200.0%. This provides the Company with increased investment flexibility but also increases the Company’s risks related to leverage. NMFC generally cannot invest in assets that are not “qualifying assets” unless at least 70.0% of its gross assets consist of “qualifying assets” immediately prior to such investment, and NMFC is not generally permitted to invest, subject to certain exceptions, in any portfolio company in which one of its affiliates currently has an investment.

NMFC recognizes that different board of director roles in risk oversight are appropriate for companies in different situations. NMFC intends to re-examine the manner in which the board of directors administers its oversight functiondepends largely on an ongoing basis to ensure that it continues to meet NMFC’s needs.

Committees of the Board of Directors

NMFC’s board of directors has established an audit committee, a nominating and corporate governance committee, a compensation committee and a valuation committee. The members of each committee have been appointed by the board of directors of NMFC and serve until their respective successor is duly elected and qualifies, unless they are removed or resign. During 2017, the board of directors of NMFC held eleven board of directors meetings, four audit committee meetings, two nominating and corporate governance committee meetings, one compensation committee meeting and eight valuation committee meetings. All directors attended at least 75.0% of the aggregate number of meetings of the board of directors and of the respective committees on

OTHER BUSINESS

Submission of Stockholder
Proposals

NMFC currently expects that the 2019 Annual Meeting of Stockholders will be held in April 2019, but the exact date, time, and location of such meeting have yet to be determined. A stockholder who intends to present a proposal at that annual meeting pursuant to the SEC’s Rule 14a-8 must submit the proposal in writing to NMFC at its address of 787 Seventh Avenue, 48th Floor, New York, New York 10019, and NMFC must receive the proposal no later than November 14, 2018, in order for the proposal to be considered for inclusion in NMFC’s proxy statement for that meeting. The submission of a proposal does not guarantee its inclusion in NMFC’s proxy statement or presentation at the meeting.

Stockholder proposals or director nominations to be presented at the 2019 Annual Meeting of Stockholders, other than stockholder proposals submitted pursuant to the SEC’s Rule 14a-8, must be delivered to, or mailed and received at, the principal executive offices of NMFC not less than 90 days or more than 120 days in advance of the one year anniversary of the date of the Annual Meeting. For the 2019 Annual Meeting of Stockholders, NMFC must receive such proposals and nominations between December 27, 2018 and January 25, 2019. If the date of the 2019 Annual Meeting of Stockholders is set to be more than 30 days prior to, or more than 60 days after, the one year anniversary of the Annual Meeting, stockholder proposals or director nominations to be timely must be so received by NMFC not less than 90 days or more than 120 days prior to the 2019 Annual Meeting of Stockholders, or prior to the tenth day following the day on which notice of the date of the 2019 Annual Meeting of Stockholders was first mailed to stockholders or publicly disclosed by NMFC. Proposals must also comply with the other requirements contained in NMFC’s Bylaws, including supporting documentation and other information. Proxies solicited by NMFC will confer discretionary voting authority with respect to these proposals, subject to SEC rules governing the exercise of this authority.

Notices of intention to present proposals at the 2019 Annual Meeting of Stockholders should be addressed to Karrie J. Jerry, Corporate Secretary, 787 Seventh Avenue, 48th Floor, New York, New York 10019. NMFC reserves the right to reject, rule out of order, or take other appropriate action with respect to any proposal that does not comply with these and other applicable requirements.

Submission of
Complaints

NMFC’s audit committee has established guidelines and procedures regarding the receipt, retention and treatment of complaints regarding accounting, internal accounting controls or auditing matters (collectively, “Accounting Matters”). Persons with complaints or concerns regarding Accounting Matters may submit their complaints to NMFC’s chief compliance officer. Persons who are uncomfortable submitting complaints to the chief compliance officer, including complaints involving the chief compliance officer, may submit complaints directly to NMFC’s audit committee chair. Complaints may also be submitted on an anonymous basis via an anonymous online reporting system.

The Chief Compliance Officer may be contacted at:

Karrie J. Jerry
Chief Compliance Officer
New Mountain Finance Corporation
787 Seventh Avenue
48th Floor
New York, New York 10019

The Audit Committee Chair may be contacted at:

Kurt J. Wolfgruber
Audit Committee Chair
New Mountain Finance Corporation
787 Seventh Avenue
48th Floor
New York, New York 10019

Other
Business

The board of directors of NMFC does not presently intend to bring any other business before the AnnualSpecial Meeting, and, so far as is known to the board of directors of NMFC, no matters may properly be brought before the AnnualSpecial Meeting except as specified in the Notice of the AnnualSpecial Meeting. As to any other business that may properly come before the AnnualSpecial Meeting, however, the proxies will be voted in respect thereof in accordance with the discretion of the proxyholders. Whether or not you expect to attend the AnnualSpecial Meeting, please vote your proxy via the Internet or request, complete, sign, date and a proxy card so that you may be represented at the AnnualSpecial Meeting.

Annual
Reports

When available, NMFC will furnish, without charge, copies of NMFC’s annual report on Form 10-K, quarterly reports on Form 10-Q and Current Reports on Form 8-K, to an investor upon request directed to New Mountain Finance Corporation, 787 Seventh Avenue, 48th Floor, New York, New York 10019, Attention: Investor Relations or by telephone at (212) 720-0300. ThereThe reports are also available at no cost through NMFC’s website at www.newmountainfinance.com or through the SEC’s EDGAR database at www.sec.gov.

Delivery Of Proxy
Materials

Please note that only one copy of the 2018this Proxy Statement and the 2017 Annual Report or Notice of AnnualSpecial Meeting of Stockholders may be delivered to two or more stockholders of record of the Company who share an address unless we have received contrary instructions from one or more of such stockholders. We will deliver promptly, upon request, a separate copy of any of these documents to stockholders of record of the Company at a shared address to which a single copy of such documents was delivered. Stockholders who wish to receive a separate copy of any of these documents, or to receive a single copy of such documents if multiple copies were delivered, now or in the future, should submit their request by calling us at (212) 720-0300 or by writing to New Mountain Finance Corporation, c/o Karrie J. Jerry, Corporate Secretary, 787 Seventh Avenue, 48th Floor, New York, New York 10019.

You are cordially invited to participate inattend the Annual Meeting.Special Meeting of stockholders. Whether or not you planexpect to attend the AnnualSpecial Meeting virtually, you are requestedplease follow the instructions on your proxy card or the enclosed voting instruction form to vote in accordance withvia the voting instructionsInternet or telephone, or sign, date and return a proxy card in the Notice of Internet Availability of Proxy Materials, or by requesting hard copy proxy materials from us and returning a proxy card.postage-paid envelope provided so that you may be represented at the Special Meeting.

	By Order of the board of directors
	Karrie J. Jerry
	Corporate Secretary
New York, New York
May 7, 2018

New York, New York
March 14, 2018

PRIVACY
NOTICE

Your privacy is very important to us. This Privacy Notice sets forth our policies with respect to non-public personal information about our stockholders and prospective and former stockholders. These policies apply to stockholders of New Mountain Finance Corporation and may be changed at any time, provided a notice of such change is given to you. This notice supersedes any other privacy notice you may have received from us.

We will safeguard, according to strict standards of security and confidentiality, all information we receive about you. The only information we collect from you is your name, address, number of shares you hold and your social security number. This information is used only so that we can send you annual reports and other information about us, and send you proxy statements or other information required by law.

We do not share this information with any non-affiliated third party except as described below.

We seek to carefully safeguard your private information and, to that end, restrict access to non-public personal information about you to those employees and other persons who need to know the information to enable us to provide services to you. We maintain physical, electronic and procedural safeguards to protect your non-public personal information.

If you have any questions regarding this policy or the treatment of your non-public personal information, please contact our chief compliance officer at (212) 655-0083.