FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * Bolus Mark J.   2. Issuer Name and Ticker or Trading Symbol COMMUNITY BANK SYSTEM, INC. [CBU] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O COMMUNITY BANK SYSTEM, INC., 5790 WIDEWATERS PARKWAY 3. Date of Earliest Transaction (Month/Day/Year) 03/20/2018 (Street) DEWITT, NY 13214 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 03/20/2018   M   583.7192 A (1) 73,224.3526 D   Common Stock               6,411.23 (2) I By Mark Bolus Trust Common Stock               194.205 I By daughter, Taylor Bolus Common Stock               194.205 I By daughter, Paige Bolus Common Stock               194.205 I By son, Austin Bolus Common Stock               194.205 I By son, Noah Bolus Common Stock               4,685.885 (3) I By Taylor Bolus Trust Common Stock               4,685.885 (3) I By Paige Bolus Trust Common Stock               4,687.375 (4) I By Austin Bolus Trust Common Stock               4,687.375 (4) I By Noah Bolus Trust

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Phantom Stock (Deferred Stock Units)

(5)

03/20/2018

A

611

(5)

(5)

Common Stock

611

$ 0

2,027

D

Phantom Stock (Deferred Compensation)

(6)

03/20/2018

M

583.7192

(6)

(6)

Common Stock

583.7192

(1)

711.0738 (7)

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Bolus Mark J. C/O COMMUNITY BANK SYSTEM, INC. 5790 WIDEWATERS PARKWAY DEWITT, NY 13214	X

Signatures

/s/ Danielle M. Cima, pursuant to a Confirming Statement executed by Mark J. Bolus		03/22/2018
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	On March 20, 2018, the reporting person's phantom stock units were settled for an equal number of shares of Community Bank System, Inc. common stock.
(2)	Includes 112.427 shares acquired pursuant to the Community Bank System, Inc. Dividend Reinvestment Plan.
(3)	Includes 85.589 shares acquired pursuant to the Community Bank System, Inc. Dividend Reinvestment Plan.
(4)	Includes 87.079 shares acquired pursuant to the Community Bank System, Inc. Dividend Reinvestment Plan.
(5)	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.
(6)	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.
(7)	Includes 36.4581 units of phantom stock acquired on January 10, 2018 under the Deferred Compensation Plan's dividend reinvestment feature.

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