[Form 4] COMMUNITY FINANCIAL SYSTEM, INC. Insider Trading Activity

Rhea-AI Filing Summary

Community Financial System, Inc. director reported updated equity holdings and deferred awards. As of the reported transaction on 12/18/2025, the director beneficially owns 11,202.421 shares of common stock directly. These holdings include shares acquired on April 10, July 10, and October 10, 2025 through the company’s Dividend Reinvestment Plan.

The director also holds deferred equity under company plans. Deferred stock units under the 2022 Long-Term Incentive Plan represent 6,963.1469 phantom stock units, each economically equivalent to one common share and to be settled in stock at predetermined dates. In addition, 189.4876 phantom stock units tied to deferred compensation were acquired on December 18, 2025 at $60.69 per unit, bringing total deferred compensation phantom units to 7,712.7297, also to be settled in common stock at future dates selected by the reporting person.

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

OMB Number:			3235-0287
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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^*

Fesette Neil E.

(Last) (First) (Middle)

C/O COMMUNITY FINANCIAL SYSTEM, INC.

5790 WIDEWATERS PARKWAY

(Street)

DEWITT 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)

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

3. Date of Earliest Transaction (Month/Day/Year)
12/18/2025

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								11,202.421(1)	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
Phantom Stock (Deferred Stock Units)	(2)							(2)	(2)	Common Stock	6,963.1469		6,963.1469(3)	D
Phantom Stock (Deferred Compensation)	(4)	12/18/2025		A		189.4876		(4)	(4)	Common Stock	189.4876	$60.69	7,712.7297(5)	D

Explanation of Responses:

1. Includes 77.194, 66.44, and 72.7280 shares acquired on April 10, 2025, July 10, 2025, and October 10, 2025, respectively, pursuant to the Community Financial System, Inc. Dividend Reinvestment Plan.

2. The reporting person has received deferred stock units under the Community Financial System, Inc. 2022 Long-Term Incentive Plan, as amended (the "Plan"). Each phantom stock unit which represents a deferred stock unit is the economic equivalent of one share of Community Financial System, Inc. common stock and will be settled in common stock at a predetermined date.

3. Includes 35.9672, 40.8617, and 45.1866 units of phantom stock acquired as dividend equivalents on April 10, 2025, July 10, 2025, and October 10, 2025, respectively, under the Plan.

4. Each unit of phantom stock is the economic equivalent of one share of Community Financial System, Inc. common stock. The units of phantom stock relating to the Deferred Compensation Plan will be settled in Community Financial System, Inc. common stock at future dates selected by the reporting person.

5. Includes 66.2494 and 75.0594 units of phantom stock acquired as dividend equivalents on July 10, 2025, and October 10, 2025, respectively, under the Deferred Compensation Plan.

	/s/ Danielle M. Cima, pursuant to a Confirming Statement executed by Neil E. Fesette	12/19/2025
	** 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.

FAQ

What insider transaction did Community Financial System, Inc. (CBU) report?

The report shows a director updating their holdings, including acquiring 189.4876 phantom stock units tied to deferred compensation on 12/18/2025 at $60.69 per unit, plus previously granted deferred stock units and common shares.

How many Community Financial System, Inc. (CBU) common shares does the director now own?

After the reported activity, the director beneficially owns 11,202.421 shares of Community Financial System, Inc. common stock directly.

What are the deferred stock units reported for Community Financial System, Inc. (CBU)?

The director holds 6,963.1469 phantom stock units under the 2022 Long-Term Incentive Plan. Each unit is the economic equivalent of one share of CBU common stock and will be settled in stock at predetermined dates.

How many phantom stock units tied to deferred compensation does the CBU director hold?

Following the 189.4876-unit acquisition on 12/18/2025, the director holds a total of 7,712.7297 phantom stock units relating to the Deferred Compensation Plan, each equivalent to one share of common stock and to be settled at future dates the director selected.

How were dividend equivalents reflected in the CBU director’s phantom stock units?

The explanation notes additional phantom stock units acquired as dividend equivalents on April 10, July 10, and October 10, 2025 under both the Long-Term Incentive Plan and the Deferred Compensation Plan, increasing the director’s deferred holdings.

What is the role of the reporting person at Community Financial System, Inc. (CBU)?

The reporting person is identified as a Director of Community Financial System, Inc. and filed the ownership report as a single reporting person.