Exhibit 32.1

CERTIFICATION PURSUANT TO 18 U.S.C. §1350,

AS ADOPTED PURSUANT TO

§906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Annual Report of ATEL 15, LLC (the “Company”) on Form 10-K for the year ended December 31, 2019 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Dean L. Cash, Chairman of the Board, President and Chief Executive Officer of ATEL Managing Member, LLC, Managing Member of the Company, hereby certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that:

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.

Date:   March 25, 2020

/s/ Dean L. Cash

Dean L. Cash

Chairman of the Board, President and

Chief Executive Officer of ATEL Managing Member, LLC,

(Managing Member)

A signed original of this written statement required by Section 906 has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request.