X0306 4 2022-03-15 0000723188 COMMUNITY BANK SYSTEM, INC. CBU 0001264816 STEELE SALLY A C/O COMMUNITY BANK SYSTEM, INC. 5790 WIDEWATERS PARKWAY DEWITT NY 13214 1 Phantom Stock (Deferred Stock Units) 2022-03-15 4 A 0 644 0 A Common Stock 644 1226.6046 D Phantom Stock (Deferred Compensation) Common Stock 9892.1316 9892.1316 D The reporting person has received deferred stock units under the Community Bank System, Inc. 2014 Long-Term Incentive Plan (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 16.4801 units of phantom stock acquired as dividend equivalents under the 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 the Deferred Compensation Plan will be settled in Community Bank System, Inc. common stock at future dates selected by the reporting person. Includes 72.3151 units of phantom stock acquired on January 10, 2022 under the Deferred Compensation Plan's dividend reinvestment feature. /s/ Danielle M. Cima, pursuant to a Confirming Statement executed by Sally A. Steele 2022-03-17