Description of the Plan	12 Months Ended
Dec. 31, 2025
EBP 019
EBP, Description of Plan [Line Items]
Description of the Plan	Description of the Plan The following description of the Mosaic Union Savings Plan (the Plan) provides only general information. Participants should refer to the Plan document for a more complete description of the Plan’s provisions. The Plan was established pursuant to collective bargaining agreements with the unions. (a)General The following union hourly employees of The Mosaic Company (the Company) are eligible to participate upon their hire date: Employees represented by Local #188‑A of the United Steelworkers of America at the Carlsbad, New Mexico operations (through April 30, 2026); Employees represented by Local #1625 International Chemical Workers Union Council of the United Food and Commercial Workers International Union at the New Wales and South Pierce, Florida operations; Employees represented by Local #35C International Chemical Workers Union Council of the United Food and Commercial Workers International Union at the Four Corners and Wingate, Florida operations; Employees represented by Locals #39C, 439C, and 814C International Chemical Workers Union Council of the United Food and Commercial Workers International Union at the Bartow, Riverview and South Fort Meade, Florida operations; Employees represented by Local #7‑662 of the United Steelworkers of America at the Pekin, Illinois operations (through May 11, 2023); Employees represented by Local #1625 International Chemical Workers Union Council of the United Food and Commercial Workers International Union at the Port Sutton, Florida facility (through December 23, 2003); Employees represented by Local #12458‑02 of the United Steelworkers of America at the Hutchinson, Kansas operations (through October 31, 2005); Employees represented by Allied‑Industrial Union and its Local #4‑227, AFL‑CIO, CLC at the Houston, Texas operations (through December 11, 2008); and Employees represented by Local #22 Bakery, Confectionary, Tobacco Workers and Grain Millers at the Savage, Minnesota operations (through September 1, 2020). Mosaic’s Global Pension Investment Committee is responsible for selecting and monitoring the investment options offered by the Plan. Mosaic's Global Pension Investment Committee may hire an investment consultant to assist with its fiduciary responsibilities. Mosaic’s Global Benefits Committee is responsible for oversight of and amending the Plan. Pursuant to certain collective bargaining agreements, newly hired represented employees are automatically enrolled in the Plan at a 6% deferral rate upon meeting the eligibility requirements. Contributions are invested in the Vanguard Target Retirement Fund that is nearest to the year the employee will reach age 65. A participant is assumed to have authorized the Company to withhold from each paycheck a union-negotiated percentage of pay on a before‑tax basis. Automatic payroll withholding can begin no sooner than 45 days from date of hire. A participant has the right to decline automatic enrollment within 45 days from date of hire. The Plan is subject to the provisions of the Employee Retirement Income Security Act of 1974 (ERISA), as amended. (b)Contributions The Plan is funded by contributions from participants in the form of payroll deductions/salary reductions from 1% to 75% of participants’ eligible pay (subject to Internal Revenue Service (IRS) annual statutory limits of $23,500 and $23,000 for 2025 and 2024, respectively) in before-tax dollars. Additional before-tax “catch-up” contributions are allowed above the IRS annual dollar limit for employees at least age 50 or who will reach age 50 during a given calendar year. Participants direct the investment of their contributions into various investment options offered by the Plan. The Plan is also funded by Company matching contributions, which are subject to certain limitations imposed by Section 415 of the Internal Revenue Code (IRC). Participants should refer to their collective bargaining agreement, summary plan description, or contact their local Human Resources to determine the specific matching contributions. Pursuant to certain collective bargaining agreements, the Company added a Defined Contribution Retirement Plan (DCRP) feature to the Plan. The Company contribution to the DCRP feature is based on a percentage of an employee’s eligible pay. Generally, a participant must be employed on the last day of the Plan year to be eligible for the DCRP contribution. For the 2025 and 2024 plan years, the Company made DCRP contributions of $7,475,359 and $7,003,309, which were funded to the Plan in 2026 and 2025, utilizing $6,112,560 for DB Surplus for the 2025 plan year. For the 2025 and 2024 plan years, the Company made true-up Company matching contributions of $42,844 and $43,638, which were funded to the Plan in 2026 and 2025, utilizing forfeitures. No allowance for credit losses has been recorded as of December 31, 2025 or 2024. Participants may roll over their vested benefits from other qualified retirement plans to the Plan. (c)Participant Accounts Each participant’s account is credited with the participant’s contributions and allocations of (a) the Company contributions, and (b) Plan earnings (losses). Each participant’s account is charged with an allocation of certain administrative expenses. The benefit to which a participant is entitled is the benefit that can be provided from the participant’s vested account. (d)Administrative Expenses Administrative expenses are to be paid by the Plan but may be paid by the Company. (e)Investments The Plan’s investments are held in the Mosaic Master Trust (the Master Trust) which is administered by Fidelity Investments. Participants can choose from investment funds offered by the Plan and may elect to change the investment direction of their existing account balances and their future contributions daily. (f)Vesting Participants are immediately vested in the portion of their Plan account related to participant contributions, Company matching contributions, and earnings thereon. Certain participants eligible for DCRP contributions are vested in their DCRP account after either three years of service, attaining age 65, or death while an employee. Forfeitures of non-vested participant accounts are used first to restore DCRP contributions for reemployed employees who are entitled to have forfeitures restored and are then used to offset employer contributions. In 2025 and 2024, Company contributions were reduced by $43,638 and $141,946, respectively, from forfeited non-vested accounts. Unused forfeitures were $359,166 and $222,523 as of December 31, 2025 or 2024, respectively. (g)Payment of Benefits Participants may withdraw their vested account balance upon termination of employment. Under certain conditions of financial hardship, participants working for the Company may withdraw certain funds. Certain withdrawals are available after age 59½ or in the event of disability. Additionally, while still employed, in‑service withdrawals are available subject to certain requirements and limitations. Subject to potential IRS penalties, participants whose employment is terminated and have a vested account balance in excess of $7,000 may receive their distribution in a lump sum or installments that commence immediately after termination or a later date, but no later than age 73. Participants may be entitled to additional forms of payment or may need to obtain spousal consent to a distribution or withdrawal if the participant had an account balance from another qualified plan, that plan was maintained by a company that was acquired by the Company, and the participant’s account balance was transferred to this Plan. (h)Notes Receivable from Participants Eligible participants may borrow from their fund accounts a minimum loan amount of $500 up to a maximum equal to the lesser of $50,000 or 50% of their account balance. Eligible participants may have one loan outstanding at any given time. Account balances attributable to the annual Company contributions are not available for loans. Loan terms range from 6 months to 5 years. The loans are secured by the balance in the participant’s account and bear interest at a fixed rate of 1% above the prevailing prime rate, as quoted in The Wall Street Journal at time of issuance. Interest rates on outstanding loans in 2025 and 2024 ranged from 4.25% to 9.5%. Principal and interest are paid through payroll deductions. (i)SECURE 2.0 Act of 2022 On December 29, 2022, the SECURE 2.0 Act of 2022 (SECURE 2.0) was enacted to help improve retirement savings. The SECURE 2.0 Act made wide-ranging changes, both mandatory and elective, to qualified plans and its provisions have various effective dates. Significant provisions include the following: •increase the required minimum distribution (RMD) age from 72 to 73, effective January 1, 2023, and to age 75, effective January 1, 2033, •reduce the excise tax for failure to take RMDs from 50 percent to 25 percent of the RMD amount that was not taken, beginning January 1, 2023, and •require all catch-up contributions for participants with compensation of more than $145,000 (indexed for inflation) to be designated as Roth 401(k) contributions beginning after December 31, 2023. NOTE: On August 25, 2023, the Internal Revenue Service announced a 2-year administrative transition period with respect to the requirement under section 603 of the SECURE 2.0 Act that catch-up contributions made on behalf of certain eligible participants be designated as Roth contributions. The Plan will incorporate changes in its Plan document and administration to the extent required by the SECURE 2.0 Act. (j)Transfer of DB Surplus On April 19, 2024, the Internal Revenue Service issued a private letter ruling allowing the surplus of the terminated Mosaic Combined U.S. Defined Benefit Plan to be transferred to a suspense account in the Mosaic Investment Plan in the amount of $6,693,605 and to the Plan in the amount of $12,430,982 to fund employer nonelective contributions. The surplus was transferred effective June 13, 2024. (k)Plan Termination Although it has not expressed any interest to do so, the Company reserves the right under the Plan (subject to the collective bargaining agreements) to make changes at any time or even suspend or terminate the Plan subject to the provisions of ERISA. Upon termination of the Plan, participants will become fully vested in all amounts in their accounts.

Description of the Plan

The following description of the Mosaic Union Savings Plan (the Plan) provides only general information. Participants should refer to the Plan document for a more complete description of the Plan’s provisions.

The Plan was established pursuant to collective bargaining agreements with the unions.

The following union hourly employees of The Mosaic Company (the Company) are eligible to participate upon their hire date:

Employees represented by Local #188‑A of the United Steelworkers of America at the Carlsbad, New Mexico operations (through April 30, 2026);

Employees represented by Local #1625 International Chemical Workers Union Council of the United Food and Commercial Workers International Union at the New Wales and South Pierce, Florida operations;

Employees represented by Local #35C International Chemical Workers Union Council of the United Food and Commercial Workers International Union at the Four Corners and Wingate, Florida operations;

Employees represented by Locals #39C, 439C, and 814C International Chemical Workers Union Council of the United Food and Commercial Workers International Union at the Bartow, Riverview and South Fort Meade, Florida operations;

Employees represented by Local #7‑662 of the United Steelworkers of America at the Pekin, Illinois operations (through May 11, 2023);

Employees represented by Local #1625 International Chemical Workers Union Council of the United Food and Commercial Workers International Union at the Port Sutton, Florida facility (through December 23, 2003);

Employees represented by Local #12458‑02 of the United Steelworkers of America at the Hutchinson, Kansas operations (through October 31, 2005);

Employees represented by Allied‑Industrial Union and its Local #4‑227, AFL‑CIO, CLC at the Houston, Texas operations (through December 11, 2008); and

Employees represented by Local #22 Bakery, Confectionary, Tobacco Workers and Grain Millers at the Savage, Minnesota operations (through September 1, 2020).

Mosaic’s Global Pension Investment Committee is responsible for selecting and monitoring the investment options offered by the Plan. Mosaic's Global Pension Investment Committee may hire an investment consultant to assist with its fiduciary responsibilities. Mosaic’s Global Benefits Committee is responsible for oversight of and amending the Plan. Pursuant to certain collective bargaining agreements, newly hired represented employees are automatically enrolled in the Plan at a 6% deferral rate upon meeting the eligibility requirements. Contributions are invested in the Vanguard Target Retirement Fund that is nearest to the year the employee will reach age 65. A participant is assumed to have authorized the Company to withhold from each paycheck a union-negotiated percentage of pay on a before‑tax basis. Automatic payroll withholding can begin no sooner than 45 days from date of hire. A participant has the right to decline automatic enrollment within 45 days from date of hire. The Plan is subject to the provisions of the Employee Retirement Income Security Act of 1974 (ERISA), as amended.

The Plan is funded by contributions from participants in the form of payroll deductions/salary reductions from 1% to 75% of participants’ eligible pay (subject to Internal Revenue Service (IRS) annual statutory limits of $23,500 and $23,000 for 2025 and 2024, respectively) in before-tax dollars. Additional before-tax “catch-up” contributions are allowed above the IRS annual dollar limit for employees at least age 50 or who will reach age 50 during a given calendar year. Participants direct the investment of their contributions into various investment options offered by the Plan. The Plan is also funded by Company matching contributions, which are subject to certain limitations imposed by Section 415 of the Internal Revenue Code (IRC). Participants should refer to their

collective bargaining agreement, summary plan description, or contact their local Human Resources to determine the specific matching contributions.

Pursuant to certain collective bargaining agreements, the Company added a Defined Contribution Retirement Plan (DCRP) feature to the Plan. The Company contribution to the DCRP feature is based on a percentage of an employee’s eligible pay. Generally, a participant must be employed on the last day of the Plan year to be eligible for the DCRP contribution.

For the 2025 and 2024 plan years, the Company made DCRP contributions of $7,475,359 and $7,003,309, which were funded to the Plan in 2026 and 2025, utilizing $6,112,560 for DB Surplus for the 2025 plan year. For the 2025 and 2024 plan years, the Company made true-up Company matching contributions of $42,844 and $43,638, which were funded to the Plan in 2026 and 2025, utilizing forfeitures. No allowance for credit losses has been recorded as of December 31, 2025 or 2024.

Participants may roll over their vested benefits from other qualified retirement plans to the Plan.

(c)Participant Accounts

Each participant’s account is credited with the participant’s contributions and allocations of (a) the Company contributions, and (b) Plan earnings (losses). Each participant’s account is charged with an allocation of certain administrative expenses. The benefit to which a participant is entitled is the benefit that can be provided from the participant’s vested account.

(d)Administrative Expenses

Administrative expenses are to be paid by the Plan but may be paid by the Company.

The Plan’s investments are held in the Mosaic Master Trust (the Master Trust) which is administered by Fidelity Investments.

Participants can choose from investment funds offered by the Plan and may elect to change the investment direction of their existing account balances and their future contributions daily.

Participants are immediately vested in the portion of their Plan account related to participant contributions, Company matching contributions, and earnings thereon. Certain participants eligible for DCRP contributions are vested in their DCRP account after either three years of service, attaining age 65, or death while an employee. Forfeitures of non-vested participant accounts are used first to restore DCRP contributions for reemployed employees who are entitled to have forfeitures restored and are then used to offset employer contributions. In 2025 and 2024, Company contributions were reduced by $43,638 and $141,946, respectively, from forfeited non-vested accounts. Unused forfeitures were $359,166 and $222,523 as of December 31, 2025 or 2024, respectively.

(g)Payment of Benefits

Participants may withdraw their vested account balance upon termination of employment. Under certain conditions of financial hardship, participants working for the Company may withdraw certain funds. Certain withdrawals are available after age 59½ or in the event of disability. Additionally, while still employed, in‑service withdrawals are available subject to certain requirements and limitations.

Subject to potential IRS penalties, participants whose employment is terminated and have a vested account balance in excess of $7,000 may receive their distribution in a lump sum or installments that commence immediately after termination or a later date, but no later than age 73. Participants may be entitled to additional forms of payment or may need to obtain spousal consent to a distribution or withdrawal if the participant had an account balance from another qualified plan, that plan was maintained by a company that was acquired by the Company, and the participant’s account balance was transferred to this Plan.

(h)Notes Receivable from Participants

Eligible participants may borrow from their fund accounts a minimum loan amount of $500 up to a maximum equal to the lesser of $50,000 or 50% of their account balance. Eligible participants may have one loan outstanding at any given time. Account balances attributable to the annual Company contributions are not available for loans. Loan terms range from 6 months to 5 years. The loans are secured by the balance in the participant’s account and bear interest at a fixed rate of 1% above the prevailing prime rate, as quoted in The Wall Street Journal at time of issuance. Interest rates on outstanding loans in 2025 and 2024 ranged from 4.25% to 9.5%. Principal and interest are paid through payroll deductions.

(i)SECURE 2.0 Act of 2022

On December 29, 2022, the SECURE 2.0 Act of 2022 (SECURE 2.0) was enacted to help improve retirement savings. The SECURE 2.0 Act made wide-ranging changes, both mandatory and elective, to qualified plans and its provisions have various effective dates. Significant provisions include the following:

•increase the required minimum distribution (RMD) age from 72 to 73, effective January 1, 2023, and to age 75, effective January 1, 2033,

•reduce the excise tax for failure to take RMDs from 50 percent to 25 percent of the RMD amount that was not taken, beginning January 1, 2023, and

•require all catch-up contributions for participants with compensation of more than $145,000 (indexed for inflation) to be designated as Roth 401(k) contributions beginning after December 31, 2023. NOTE: On August 25, 2023, the Internal Revenue Service announced a 2-year administrative transition period with respect to the requirement under section 603 of the SECURE 2.0 Act that catch-up contributions made on behalf of certain eligible participants be designated as Roth contributions.

The Plan will incorporate changes in its Plan document and administration to the extent required by the SECURE 2.0 Act.

(j)Transfer of DB Surplus

On April 19, 2024, the Internal Revenue Service issued a private letter ruling allowing the surplus of the terminated Mosaic Combined U.S. Defined Benefit Plan to be transferred to a suspense account in the Mosaic Investment Plan in the amount of $6,693,605 and to the Plan in the amount of $12,430,982 to fund employer nonelective contributions. The surplus was transferred effective June 13, 2024.

Although it has not expressed any interest to do so, the Company reserves the right under the Plan (subject to the collective bargaining agreements) to make changes at any time or even suspend or terminate the Plan subject to the provisions of ERISA. Upon termination of the Plan, participants will become fully vested in all amounts in their accounts.