X0306 4 2023-01-17 0000723188 COMMUNITY BANK SYSTEM, INC. CBU 0001485738 Fesette Neil E. C/O COMMUNITY BANK SYSTEM, INC. 5790 WIDEWATERS PARKWAY DEWITT NY 13214 1 Common Stock 2023-01-17 4 M 0 633.3678 0 A 8585.8069 D Phantom Stock (Deferred Compensation) 2023-01-17 4 M 0 633.3678 0 D Common Stock 633.3678 7071.9751 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 47.4236, 50.8174, 54.984, and 52.5636 units of phantom stock acquired on April 11, 2022, July 11, 2022, October 10, 2022, and January 10, 2023, respectively, under the Deferred Compensation Plan's dividend reinvestment feature. /s/ Danielle M. Cima, pursuant to a Confirming Statement executed by Neil E. Fesette 2023-01-19