X0306 4 2023-03-14 0000723188 COMMUNITY BANK SYSTEM, INC. CBU 0001220435 DAVIS JEFFREY L C/O COMMUNITY BANK SYSTEM, INC. 5790 WIDEWATERS PARKWAY DEWITT NY 13214 1 Phantom Stock (Deferred Compensation) Common Stock 6127.946 6127.946 D Phantom Stock (Deferred Compensation under Merchants plan) Common Stock 52073.3589 52073.3589 D Phantom Stock (Deferred Stock Units) 2023-03-14 4 A 0 1154 0 A Common Stock 1154 4666.5856 D Each unit of phantom stock is the economic equivalent of one share of Community Bank System, Inc. common stock. The units of phantom stock relating to the Deferred Compensation Plan will be settled in Community Bank System, Inc. common stock at future dates selected by the reporting person. Includes 144.5157 units of phantom stock acquired under the Deferred Compensation Plan's dividend reinvestment feature. The units of phantom stock were acquired through Merchants deferred compensation plan. Each unit of phantom stock is the economic equivalent of one share of Community Bank System, Inc. common stock. The units of phantom stock relating to such deferred compensation plan will be settled in Community Bank System, Inc. common stock at future dates selected by the reporting person. Includes 1,585.1336 units of phantom stock acquired under the Merchants' deferred compensation plan's dividend reinvestment feature. The reporting person has received deferred stock units under the Community Bank 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 Bank System, Inc. common stock and will be settled in common stock at a predetermined date. Includes 93.5056 units of phantom stock acquired as dividend equivalents under the Plan. /s/ Danielle M. Cima, pursuant to a Confirming Statement executed by Jeffrey L. Davis 2023-03-15