Michele Sullivan - 18 Dec 2025 Form 4 Insider Report for COMMUNITY FINANCIAL SYSTEM, INC. (CBU)

Role
Director
Signature
/s/ Danielle M. Cima, pursuant to Confirming Statement executed by Michele Sullivan
Issuer symbol
CBU
Transactions as of
18 Dec 2025
Net transactions value
+$24,875
Form type
4
Filing time
19 Dec 2025, 15:50:53 UTC
Previous filing
22 Sep 2025
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Sullivan Michele Director C/O COMMUNITY FINANCIAL SYSTEM, INC., 5790 WIDEWATERS PARKWAY, DEWITT /s/ Danielle M. Cima, pursuant to Confirming Statement executed by Michele Sullivan 19 Dec 2025 0002009605

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 Deferred Stock (Deferred Compensation) Award $24,875 +410 +15% $60.69 3,063 18 Dec 2025 Common Stock 410 Direct F3, F4
holding CBU Phantom Stock (Deferred Stock Units) 2,712 18 Dec 2025 Common Stock 2,712 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 "LTIP"). 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 12.7836, 20.6277, and 22.811 units of phantom stock acquired as dividend equivalents on April 10, 2025, July 10, 2025, and October 10, 2025, respectively, under the LTIP.
F3 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 for Directors (the "DCP for Directors"), will be settled in Community Financial System, Inc. common stock at future dates selected by the reporting person.
F4 Includes 13.3543, and 18.8141 units of phantom stock acquired on July 10, 2025, and October 10, 2025, respectively, under the DCP for Directors.