Exhibit 32.1

Certification Pursuant to Section 906

of the Sarbanes-Oxley Act of 2002 (18 U.S.C. Section 1350)

The undersigned, the Chief Executive Officer of ASGN Incorporated (the "Company"), hereby certifies that, to his knowledge on the date hereof:

(a) the Quarterly Report on Form 10-Q of the Company for the period ended September 30, 2024 filed on the date hereof with the Securities and Exchange Commission (the "Report") fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

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

Date: October 30, 2024	/s/ Theodore S. Hanson
	Theodore S. Hanson
	Chief Executive Officer
	(Principal Executive Officer)