United States Securities and Exchange Commission Washington, D.C. 20549 FORM 10-K (MARK ONE) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year 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 001-31921 Compass Minerals International, Inc. (Exact name of registrant as specified in its charter) Delaware 36- ...