X0306 4 2023-03-14 0000723188 COMMUNITY BANK SYSTEM, INC. CBU 0001264816 STEELE SALLY A C/O COMMUNITY BANK SYSTEM, INC. 5790 WIDEWATERS PARKWAY DEWITT NY 13214 1 Common Stock 2023-03-15 4 P 0 2000 53.4617 A 4585 I Joint with brother Common Stock 42372.2727 D Phantom Stock (Deferred Compensation) Common Stock 6797.6446 6797.6446 D Phantom Stock (Deferred Stock Units) 2023-03-14 4 A 0 1154 0 A Common Stock 1154 1819.4495 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 271.5449 units of phantom stock acquired under the 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 21.3317 units of phantom stock acquired as dividend equivalents under the Plan. /s/ Danielle M. Cima, pursuant to a Confirming Statement executed by Sally A. Steele 2023-03-16