Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2021 Or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 000-50796 SP Plus Corporation (Exact Name of Registrant as Specified in Its Charter) (State or Other Jurisdiction of (I.R.S. ...

UNITED STATES FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2020 Or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 000-50796 SP PLUS CORPORATION (Exact Name of Registrant as Specified in Its Charter) SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 (Registrant's Telephone Number, Including Area Code) Securitie ...