COMMUNITY FINANCIAL SYSTEM, INC. — Director's Dealing 2017

Dec 22, 2017

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: COMMUNITY BANK SYSTEM, INC. (CBU)
CIK: 0000723188
Period of Report: 2017-12-21

Reporting Person: DONAHUE BRIAN D (EVP & Chief Banking Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2017-12-21	Common Stock	M	5535	$18.09	Acquired	43844	Direct
2017-12-21	Common Stock	S	5535	$55.1908	Disposed	38309	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2017-12-21	Stock Option	$18.09	M	5535	Disposed	2018-01-16	Common Stock (5535)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	8134.6095	Indirect

Footnotes

F1: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $55.05 to $55.36, inclusive. The reporting person undertakes to provide Community Bank System, Inc., any security holder of Community Bank System, Inc. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2: The number of shares reported herein were acquired pursuant to Community Bank System, Inc.'s 401(K) Plan and are based on a current plan statement.

F3: The option vested ratably on January 16, 2009, 2010, 2011, 2012, and 2013.