Mosaic (MOS) accounting chief nets shares after RSU and performance unit vesting

Rhea-AI Filing Summary

Mosaic Co principal accounting officer Russell A. Flugel reported routine equity compensation activity. On March 9, 2026, 4,437 restricted stock units were exercised into an equal number of Mosaic common shares, and an additional 1,108 common shares were issued when a prior performance unit award vested.

To cover related tax obligations, 2,384 shares of common stock were disposed of at $26.92 per share through share withholding rather than an open-market sale. Following these transactions, Flugel directly holds 12,461 Mosaic common shares and several outstanding restricted stock unit awards, including one that is scheduled to vest 33%, 66% and 100% on March 4, 2027, 2028 and 2029.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Flugel Russell A

(Last) (First) (Middle)

C/O THE MOSAIC COMPANY

101 EAST KENNEDY BLVD, SUITE 2500

(Street)

TAMPA FL 33602

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
MOSAIC CO [ MOS ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Principal Accounting Officer

3. Date of Earliest Transaction (Month/Day/Year)
03/09/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/09/2026		M		4,437	A	$0	13,737	D
Common Stock	03/09/2026		M(1)		1,108	A	$0	14,845	D
Common Stock	03/09/2026		F(2)		2,384	D	$26.92	12,461	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Restricted Stock Units	$0(3)	03/09/2026		M			4,437	03/09/2026	(4)	Common Stock	4,437	$0	0	D
Restricted Stock Units	$0(3)							(5)	(4)	Common Stock	8,074		8,074	D
Restricted Stock Units	$0(3)							03/05/2027	(4)	Common Stock	8,540		8,540	D
Restricted Stock Units	$0(3)							11/18/2027	(4)	Common Stock	6,199		6,199	D
Restricted Stock Units	$0(3)							03/04/2028	(4)	Common Stock	11,560		11,560	D

Explanation of Responses:

1. Shares Issued to reporting person upon the vesting of a performance unit award granted to reporting person on March 9, 2023. The performance unit award was not a derivative security.

2. Shares sold to cover tax liability incurred as a result of most recent vesting of restricted stock and performance units.

3. One-for-One

4. Not Applicable

5. The Restricted Stock Unit will vest a cumulative vesting percentage equal to 33% on March 4, 2027, 66% on March 4, 2028 and 100% on March 4, 2029.

Remarks:

	/s/ Philip E. Bauer, Attorney-in-Fact for Russell A. Flugel	03/11/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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FAQ

What insider transaction did Mosaic (MOS) report for Russell A. Flugel?

Mosaic’s principal accounting officer Russell A. Flugel exercised 4,437 restricted stock units and received 1,108 common shares from a vested performance unit award. These equity awards are part of his compensation and increased his direct ownership before required tax withholding reduced the net shares retained.

How many Mosaic (MOS) shares did Russell A. Flugel dispose of for taxes?

Flugel disposed of 2,384 Mosaic common shares at $26.92 per share to cover tax liabilities from recent vesting of restricted stock and performance units. This was a tax-withholding transaction, not an open-market sale, and is a common mechanism for handling equity award taxes.

What is Russell A. Flugel’s Mosaic (MOS) shareholding after this Form 4?

After the reported transactions, Russell A. Flugel directly holds 12,461 Mosaic common shares. In addition to these shares, he also has multiple outstanding restricted stock unit awards that can convert into additional shares as they vest over future dates.

What restricted stock units does Russell A. Flugel still hold at Mosaic (MOS)?

Flugel continues to hold several restricted stock unit awards, each tied one-for-one to Mosaic common stock. One notable award will vest on a cumulative basis of 33%, 66%, and 100% on March 4, 2027, March 4, 2028, and March 4, 2029, respectively, if vesting conditions are met.

Was the Mosaic (MOS) insider transaction a market sale or tax withholding?

The disposition of 2,384 Mosaic shares was for tax withholding, not a discretionary market sale. Shares were delivered to satisfy tax liabilities triggered by the vesting of restricted stock and performance units, which is a standard administrative step for equity-based compensation.

How many restricted stock units did Russell A. Flugel exercise at Mosaic (MOS)?

Flugel exercised 4,437 restricted stock units, converting them into an equal number of Mosaic common shares at a conversion price of $0.00. This reflects the vesting of previously granted equity awards rather than an open-market purchase of shares.