COMMUNITY FINANCIAL SYSTEM, INC. — Director's Dealing 2021

May 21, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: COMMUNITY BANK SYSTEM, INC. (CBU)
CIK: 0000723188
Period of Report: 2021-05-19

Reporting Person: SUTARIS JOSEPH E (EVP & Chief Financial Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-05-19	Common Stock	M	1796	$37.77	Acquired	9716.9958	Direct
2021-05-19	Common Stock	F	1279	$79.33	Disposed	8437.9958	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2021-05-19	Stock Option	$37.77	M	1796	Disposed	2024-03-19	Common Stock (1796)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	1906.9496	Indirect

Footnotes

F1: The option vested ratably on March 19, 2015, 2016, 2017, 2018 and 2019.