John Parente - 16 Dec 2025 Form 4 Insider Report for COMMUNITY FINANCIAL SYSTEM, INC. (CBU)

Role: Director
Signature: /s/ Danielle M. Cima, pursuant to a Confirming Statement executed by John Parente
Issuer symbol: CBU
Transactions as of: 16 Dec 2025
Net transactions value: -$30.02
Form type: 4
Filing time: 17 Dec 2025, 13:55:44 UTC
Previous filing: 16 Apr 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Parente John	Director	C/O COMMUNITY FINANCIAL SYSTEM, INC., 5790 WIDEWATERS PARKWAY, DEWITT	/s/ Danielle M. Cima, pursuant to a Confirming Statement executed by John Parente	17 Dec 2025	0001486057

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	CBU	Common Stock	Options Exercise	$161,433	+4,246	+6.1%	$38.02	74,074	16 Dec 2025	Direct
transaction	CBU	Common Stock	Tax liability	$161,463	-2,683	-3.6%	$60.18	71,391	16 Dec 2025	Direct

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	CBU	Stock Option	Options Exercise	$0	-4,246	-100%	$0.000000	0	16 Dec 2025	Common Stock	4,246	$38.02	Direct
holding	CBU	Phantom Stock (Deferred Stock Units)						1,245	16 Dec 2025	Common Stock	1,245	$0.000000	Direct	F1, F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	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.
F2	Includes 9.4706, and 10.4729 units of phantom stock acquired on July 10, 2025, and October 10, 2025, respectively, as dividend equivalents under the Plan.