X0306 4 2023-01-03 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 2023-01-03 4 M 0 3366.0319 0 A 42372.2727 D Common Stock 2585 I Joint with brother Phantom Stock (Deferred Compensation) 2023-01-03 4 M 0 3366.0319 0 D Common Stock 3366.0319 6526.0997 D On January 3, 2023, the reporting person's phantom stock units were settled for an equal number of shares of Community Bank System, Inc. common stock. 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 69.0288, 73.4281, and 77.8631 units of phantom stock acquired on April 9, 2021, July 9, 2021 and October 8, 2021, respectively under the Deferred Compensation Plan's dividend reinvestment feature. /s/ Danielle M. Cima, pursuant to a Confirming Statement executed by Sally A. Steele 2023-01-04