UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 10-K x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 (the "Act") For the fiscal year ended December 31, 2018 o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number 000-20540 ASGN Incorporated (Exact name of registrant as specified in its charter) Delaware 95-4023433 (State or other jurisdiction of (I.R.S. Employer incorporation or organi ...