Form POSASR - Post-effective Amendment to an automatic shelf registration statement (2024)

As filed with the Securities and Exchange Commission on May10, 2024

Registration No.333-269190

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Post-Effective Amendment No.1

to

Form S-3

REGISTRATION STATEMENT

UNDER

THESECURITIES ACT OF 1933

Claros Mortgage Trust, Inc.

(Exact name of registrant as specified in its charter)

c/o Mack Real Estate Credit Strategies, L.P.

60 Columbus Circle, 20th Floor, New York, NY 10023

Tel: (212) 484-0050

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

J.D. Siegel, Esq.

GeneralCounsel

c/o Mack Real Estate Credit Strategies, L.P.

60 Columbus Circle, 20th Floor, New York, NY 10023

Tel: (212) 484-0050

(Address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Brent T. Epstein, Esq.

Latham& Watkins LLP

355 South Grand Avenue

LosAngeles, CA 90071

Tel: (213) 485-1234

APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC: From time to time after the effective date of this registration statement.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the followingbox. ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 underthe Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box andlist the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form isa post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective on filingwith the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. ☒

If this Form is a post-effective amendment toa registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-acceleratedfiler, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition periodfor comply with any new or revised financial accounting standards provided pursuant to Section7(a)(2)(B) of Securities Act. ☐

EXPLANATORY NOTE

Claros Mortgage Trust, Inc. is filing this Post-Effective Amendment No.1 (the “Amendment”) to its Registration Statement on Form S-3 (Registration No.333-269190) (the “Registration Statement”) solely for the purpose of amending Exhibit 107, an incorrect version of which was inadvertentlyfiled with the initial filing of the Registration Statement. Accordingly, this Amendment consists only of the facing page, this explanatory note, Exhibit 107 and the signature page to the Amendment. The remainder of the Registration Statement,including the prospectus and all other exhibits, is unchanged and has been omitted.

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the registrant certifies that it has reasonable grounds to believethat it meets all of the requirements for filing on Form S-3 and has duly caused this Post-Effective Amendment No.1 to the Registration Statement to be signed on its behalf by the undersigned, thereuntoduly authorized, in the City of New York, New York, on May10, 2024.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Post-Effective AmendmentNo.1 to the Registration Statement has been signed below by the following persons on behalf of the registrant in the capacities and on the dates indicated.

Exhibit 107

Calculation of Fling Fee Tables

Form S-3

(Form Type)

Claros MortgageTrust, Inc.

(Exact Name of Registrant as Specified in its Charter)

Table 1: Newly Registered and Carry Forward Securities