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 September 30, 2023 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: 000-51734 Calumet Specialty Products Partners, L.P. (Exact Name of Registrant as Specified in Its Charter) Delaware 35-1811116 (State or O ...