X0306 4 2020-03-16 0000723188 COMMUNITY BANK SYSTEM, INC. CBU 0001475265 Pecor Raymond C III C/O COMMUNITY BANK SYSTEM, INC. 5790 WIDEWATERS PARKWAY DEWITT NY 13214 1 Common Stock 2020-03-16 4 M 0 307.0985 0 A 6929.2585 D Common Stock 2020-03-16 4 M 0 1031.1078 0 A 7960.3663 D Common Stock 8359.383 I By Trust Phantom Stock (Deferred Stock Units) 2020-03-16 4 M 0 307.0985 0 D Common Stock 307.0985 622.9858 D Phantom Stock (Deferred Compensation) 2020-03-16 4 M 0 1031.1078 0 D Common Stock 1031.1078 1082.9556 D Phantom Stock (Deferred Stock Units) 2020-03-17 4 A 0 667 0 A Common Stock 667 1289.9858 D On March 16, 2020, the reporting person's deferred stock units were settled for an equal number of shares of Community Bank System, Inc. common stock. Includes an additional 785.056 shares to update the number of shares reported. On March 16, 2020, the reporting person's phantom stock units were settled for an equal number of shares of Community Bank System, Inc. common stock. Includes an additional 1,967.383 shares to update the number of shares held by the two trusts established for the benefit of the reporting person's niece and nephew. The reporting person is the trustee of the trusts. The reporting person disclaims beneficial ownership of these securities, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or any other purpose. The reporting person has received deferred stock units under the Community Bank System, Inc. 2014 Long-Term Incentive 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 5.3712 units of phantom stock acquired on January 10, 2029 as dividend equivalents under the 2014 Long-Term Incentive Compensation Program. 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 9.9531 units of phantom stock acquired on January 10, 2020 under the Deferred Compensation Plan's dividend reinvestment feature. Danielle M. Cima, pursuant to a Confirming Statement executed by Raymond C. Pecor, III 2020-03-18