AG Twin Brook BDC 10-Q 2023 Q1 Quarterly report

Exhibit 32.1

CERTIFICATIONS PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

(18 U.S.C. SECTION 1350)

In connection with the Quarterly Report of AG Twin Brook BDC, Inc., a Delaware corporation (the “Company”), on Form 10-Q for the quarter ended March 31, 2023, as filed with the Securities and Exchange Commission (the “Report”), Trevor Clark, Chief Executive Officer and President of the Company, does hereby certify, pursuant to § 906 of the Sarbanes-Oxley Act of 2002 (18 U.S.C. § 1350), that to his knowledge:

(1)The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2)The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ Trevor Clark

Trevor Clark

Chief Executive Officer and President

May 12, 2023