Equity awards for Community Financial System (CBU) EVP Gillan-Myer

Rhea-AI Filing Summary

COMMUNITY FINANCIAL SYSTEM, INC. executive Maureen A. Gillan-Myer, EVP and Chief Administration & HR Officer, received new equity awards. On March 17, 2026 she was granted 1,275 restricted stock units, each representing one share of common stock, which vest in three equal installments beginning March 1, 2027.

She was also granted stock options on 4,871 shares of common stock at an exercise price of $56.64 per share. These options vest ratably on March 17 of 2027, 2028, 2029, 2030 and 2031, and expire in 2036. After these awards, she holds 6,647 common shares directly and 250.8975 shares indirectly through the company’s 401(k) plan, based on a current plan statement.

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 NEW YORK 13214

(City) (State) (Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
03/17/2026

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

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

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

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								6,647	D
Common Stock								250.8975(1)	I	By 401(k) Plan

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	(2)	03/17/2026		A		1,275		(3)	(3)	Common Stock	1,275	$0	1,275	D
Stock Option	$56.64	03/17/2026		A		4,871		(4)	03/17/2036	Common Stock	4,871	$0	4,871	D

Explanation of Responses:

1. 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.

2. Each restricted stock unit represents a contingent right to receive on share of Community Financial System, Inc. common stock.

3. The restricted stock units vest in three equal installments beginning March 1, 2027.

4. The option vests ratably on March 17, 2027, 2028, 2029, 2030, and 2031.

	/s/ Danielle M. Cima, pursuant to a Confirming Statement executed by Maureen Gillan-Myer	03/19/2026
	** 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transactions did Community Financial System (CBU) report for Maureen Gillan-Myer?

Maureen Gillan-Myer received new equity awards, not open-market trades. She was granted 1,275 restricted stock units and stock options on 4,871 shares of common stock, all as compensation awards on March 17, 2026, with multi-year vesting schedules.

How many restricted stock units were granted to Maureen Gillan-Myer at Community Financial System (CBU)?

She was granted 1,275 restricted stock units. Each unit represents a contingent right to receive one share of Community Financial System common stock. These units vest in three equal installments starting March 1, 2027, spreading the award over several years.

What are the vesting terms of the new stock options granted to Maureen Gillan-Myer at CBU?

Her new stock options cover 4,871 shares at a $56.64 exercise price. The options vest ratably on March 17 of 2027, 2028, 2029, 2030 and 2031, providing a five-year vesting schedule, and are scheduled to expire in 2036 if not exercised.

How many Community Financial System (CBU) shares does Maureen Gillan-Myer hold after these awards?

Following these awards, she holds 6,647 shares of common stock directly. She also has an indirect interest in 250.8975 shares through Community Financial System’s 401(k) plan, with that figure based on a current plan statement disclosed in the filing.

What does the 401(k) plan holding disclosure mean in the CBU Form 4?

The filing notes 250.8975 shares acquired through Community Financial System’s 401(k) plan. This figure comes from a current plan statement and reflects her indirect ownership in company stock held within the retirement plan, separate from her directly held common shares.

Are Maureen Gillan-Myer’s reported CBU transactions open-market buys or compensation awards?

The reported transactions are compensation-related awards, not open-market purchases. The Form 4 shows grants of 1,275 restricted stock units and stock options on 4,871 shares, both coded as awards, with no open-market buying or selling activity reported in this filing.