Community Financial (NYSE: CBU) EVP reports stock vesting and tax-withholding share disposition

Rhea-AI Filing Summary

Community Financial System, Inc. executive Maureen A. Gillan-Myer received a performance-based restricted stock award vesting on March 4, 2026. She acquired 2,562.0628 shares of common stock, including 2,304 shares from the 2023 performance award and 258.0628 shares through the dividend reinvestment feature of the 2022 Long-Term Incentive Plan.

To cover taxes on the vesting, 943.0628 shares of common stock were disposed of at a price of $59.87 per share, reducing her directly held balance to 6,647 shares. She also has indirect ownership of 175.835 shares through the company’s 401(k) plan based on a current plan statement.

Insider Trade Summary

3 transactions reported

Mixed 3 txns

Insider Gillan-Myer Maureen A

Role EVP, Chief Admin & HR Officer

Type	Security	Shares	Price	Value
Grant/Award	Common Stock	2,562.063	$0.00	--
Tax Withholding	Common Stock	943.063	$59.87	$56K
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 7,590.063 shares (Direct); Common Stock — 175.835 shares (Indirect, By 401(k) Plan)

Footnotes (1)

1. On March 4, 2026, the Compensation Committee approved the vesting of the three-year performance-based restricted stock award, granted to the reporting person in 2023, based on achievement of predetermined performance criteria at the target level. The reporting person received 2,304 shares of common stock under the award and 258.0628 shares of common stock acquired under the dividend reinvestment feature of the Community Financial System, Inc. 2022 Long-Term Incentive Plan, as amended (the "Plan"). Payment of tax liability associated with vesting of restricted stock awards. The number of shares reported herein acquired pursuant to Community Financial System, Inc.'s 401(k) Plan and are based on a current plan statement.

Form 4 Insider Transactions: What Each Field Means →

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

OMB APPROVAL

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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^*

Gillan-Myer Maureen A

(Last) (First) (Middle)

C/O COMMUNITY FINANCIAL SYSTEM, INC.

333 BUTTERNUT DRIVE

(Street)

SYRACUSE NY 13214

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
COMMUNITY FINANCIAL SYSTEM, INC. [ CBU ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP, Chief Admin & HR Officer

3. Date of Earliest Transaction (Month/Day/Year)
03/04/2026

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	03/04/2026		A		2,562.0628(1)	A	$0	7,590.0628	D
Common Stock	03/04/2026		F(2)		943.0628	D	$59.87	6,647	D
Common Stock								175.835	I	By 401(k) Plan(3)

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

Explanation of Responses:

1. On March 4, 2026, the Compensation Committee approved the vesting of the three-year performance-based restricted stock award, granted to the reporting person in 2023, based on achievement of predetermined performance criteria at the target level. The reporting person received 2,304 shares of common stock under the award and 258.0628 shares of common stock acquired under the dividend reinvestment feature of the Community Financial System, Inc. 2022 Long-Term Incentive Plan, as amended (the "Plan").

2. Payment of tax liability associated with vesting of restricted stock awards.

3. The number of shares reported herein acquired pursuant to Community Financial System, Inc.'s 401(k) Plan and are based on a current plan statement.

	/s/ Danielle M. Cima, pursuant to a Confirming Statement executed by Maureen Gillan-Myer	03/06/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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FAQ

What insider transactions did CBU executive Maureen Gillan-Myer report on March 4, 2026?

She reported vesting of a performance-based restricted stock award, acquiring 2,562.0628 CBU common shares. This reflected 2,304 shares from a 2023 grant plus 258.0628 dividend reinvestment shares under the 2022 Long-Term Incentive Plan.

How many Community Financial System (CBU) shares were used to pay taxes on the vesting?

A total of 943.0628 CBU common shares were disposed of to pay tax liabilities related to the vesting. These shares were valued at $59.87 per share, according to the reported transaction price in the filing.

What is Maureen Gillan-Myer’s direct CBU share ownership after these transactions?

After the award vesting and tax-withholding disposition, Maureen Gillan-Myer directly holds 6,647 shares of Community Financial System common stock. This figure reflects the net result of the acquisition and the shares delivered for taxes.

What was the source of the 2,562.0628 CBU shares acquired by Maureen Gillan-Myer?

The 2,562.0628 shares came from a three-year performance-based restricted stock award granted in 2023 and a dividend reinvestment feature. She received 2,304 shares from the award and 258.0628 additional shares via dividend reinvestment under the 2022 Long-Term Incentive Plan.

Does Maureen Gillan-Myer have indirect Community Financial System (CBU) share ownership?

Yes. She has indirect ownership of 175.835 CBU common shares through the company’s 401(k) plan. The number of shares is based on a current plan statement, as described in the filing’s footnotes.

What do the transaction codes A and F mean in this CBU Form 4 filing?

Code A represents a grant, award, or other acquisition of CBU common stock tied to equity compensation vesting. Code F represents a disposition of shares used to pay tax liabilities or exercise costs associated with the restricted stock awards.