FORM 11-K ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF1934 For the fiscal year ended December31, 2025 OR TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACTOF 1934 For the transition period fromto Commission file number 001-32327 Full title of the plan and the address of the plan, if different from that of the issuer named below: MOSAIC INVESTMENT PLAN Name of issuer of the securities held pursuant to the plan and the address of its principal executive office: The Mosaic Company101 East Kennedy BoulevardSuite 2500Tampa, Florida 33602813-775-4200 MOSAIC INVESTMENT PLAN Plan No.004 Financial Statements and Supplemental Schedule December31, 2025 and 2024 (Report of Independent Registered Public Accounting Firm) MOSAIC INVESTMENT PLAN Plan No. 004 Table of Contents Supplemental Schedule ScheduleH, Line4i – Schedule of Assets (Held at End of Year) All other schedules required by Section 2520.103-10 of the Department of Labor’s Rules and Regulations forReporting and Disclosure under the Employee Retirement Income Security Act of 1974 have been omitted becausethey are not applicable. To the Plan Participants and Plan AdministratorMosaic Investment Plan: Opinion on the Financial Statements We have audited the accompanying statements of net assets available for benefits of Mosaic Investment Plan(the Plan) as of December 31, 2025 and 2024, the related statements of changes in net assets available forbenefits for the years ended December 31, 2025 and 2024, and the related notes (collectively, the financialstatements). In our opinion, the financial statements present fairly, in all material respects, the net assetsavailable for benefits of the Plan as of December 31, 2025 and 2024, and the changes in net assets availablefor benefits for the years ended December 31, 2025 and 2024, in conformity with U.S. generally acceptedaccounting principles. Basis for Opinion These financial statements are the responsibility of the Plan’s management. Our responsibility is to express anopinion on these financial statements based on our audits. We are a public accounting firm registered with thePublic Company Accounting Oversight Board (United States) (PCAOB) and are required to be independentwith respect to the Plan in accordance with the U.S. federal securities laws and the applicable rules andregulations of the Securities and Exchange Commission and the PCAOB. We conducted our audits in accordance with the standards of the PCAOB. Those standards require that weplan and perform the audit to obtain reasonable assurance about whether the financial statements are free ofmaterial misstatement, whether due to error or fraud. Our audits included performing procedures to assess therisks of material misstatement of the financial statements, whether due to error or fraud, and performingprocedures that respond to those risks. Such procedures included examining, on a test basis, evidenceregarding the amounts and disclosures in the financial statements. Our audits also included evaluating theaccounting principles used and significant estimates made by management, as well as evaluating the overallpresentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion. Accompanying Supplemental Information The Schedule H, line 4i - Schedule of Assets (Held at End of Year) as of December 31, 2025 has beensubjected to audit procedures performed in conjunction with the audit of the Plan’s financial statements. Thesupplemental information is the responsibility of the Plan’s management. Our audit procedures includeddetermining whether the supplemental information reconciles to the financial statements or the underlyingaccounting and other records, as applicable, and performing procedures to test the completeness andaccuracy of the information presented in the supplemental information. In forming our opinion on thesupplemental information, we evaluated whether the supplemental information, including its form and content,is presented in conformity with the Department of Labor’s Rules and Regulations for Reporting and Disclosureunder the Employee Retirement Income Security Act of 1974. In our opinion, the supplemental information isfairly stated, in all material respects, in relation to the financial statements as a whole. /s/ KPMG LLP We have served as the Plan’s auditor since 2005. Houston, TexasJune29, 2026 MOSAIC INVESTMENT PLAN Plan No.004 Statements of Net Assets Available for Benefits December31, 2025 and 2024 MOSAIC INVESTMENT PLAN Plan No.004 MOSAIC INVESTMENT PLAN Plan No.004 Notes to Financial Statements December31, 2025 and 2024 (1)Description of the Plan The following description of the Mosaic Investment Plan (thePlan) provides only general information. Participants should refer to thePlan document for a more complete description of the Plan’s provisions. (a)General The Plan was established on March 1, 19