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): February 5, 2020

NMF SLF I, Inc.

(Exact name of registrant as specified in its charter)

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

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 x

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 February 3, 2020, NMF SLF I, Inc. (the “Company”) delivered a capital drawdown notice to its investors relating to the sale of 5,249,900 shares of common stock, par value $0.001 per share (the “Shares”), for an aggregate offering price of $52,499,000. No underwriting discounts or commissions have been or will be paid in connection with the sale of such Shares. The sale is expected to close on February 18, 2020.

The sale of the Shares is being made pursuant to subscription or commitment agreements entered into by the Company and its investors. Under the terms of the subscription and commitment agreements, the investors are required to fund drawdowns to purchase shares of the Company’s common stock up to the amount of their capital commitments on an as-needed basis with a minimum of 10 business days’ prior notice to the investors.

The issuance and sale of the Shares are exempt from the registration requirements of the Securities Act of 1933, as amended (the “Securities Act”), pursuant to Section 4(a)(2) thereof and Regulation D thereunder. Each purchaser of the Shares was required to represent that it is (i) an “accredited investor” as defined in Rule 501 of Regulation D under the Securities Act and (ii) was acquiring the Shares for investment and not with a view to resell or distribute. The Company did not engage in general solicitation or advertising and did not offer securities to the public in connection with such issuances.

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.