CBU / Community Financial System, Inc. - تصريحات هيئة الأوراق المالية والبورصات، التقرير السنوي، بيان الوكيل

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-13695 (Ex

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 21, 2025 (Exact name of regi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 21, 2025 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 22, 2025 (Exact name of regi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 22, 2025 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employe

Marya Burgio Wlos, EVP & Chief Financial Officer Office: (315) 299-2946

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Marya Burgio Wlos, EVP & Chief Financial Officer Office: (315) 299-2946 Community Financial System, Inc. Reports Second Quarter 2025 Results SYRACUSE, N.Y. — July 22, 2025 — Community Financial System, Inc. (the “Company”) (NYSE: CBU) reported second quarter 2025 results that are included

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 24, 2025 (Exact name of regi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 24, 2025 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employe

Community Bank Accelerates Greater Lehigh Valley PA Expansion

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Marya Burgio Wlos, EVP & Chief Financial Officer Office: (315) 299-2946 Community Bank Accelerates Greater Lehigh Valley PA Expansion SYRACUSE, N.Y. — June 25, 2025 — Community Bank, N.A. (“Community Bank”), a subsidiary of Community Financial System, Inc. (NYSE: CBU), announced today it

United States SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K

United States SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 ¨ TRANSITION REPORT PURSUANT TO SECTION 15 (d) OF THE SECURITIES AND EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 001-13695 A. Full title of the plan

Filing fee table

Calculation of Filing Fee Tables S-8 COMMUNITY FINANCIAL SYSTEM, INC. Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee 1 Equity Common Stock, par value $1.00 per share 457(a) 1,500,000 $ 55.37 $ 83,055,000.00 0.0001531 $ 12,715.

As filed with the Securities and Exchange Commission on May 30, 2025

As filed with the Securities and Exchange Commission on May 30, 2025 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 21, 2025 (Exact name of regis

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 21, 2025 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-13695 (E

Marya Burgio Wlos, EVP & Chief Financial Officer Office: (315) 299-2946

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Marya Burgio Wlos, EVP & Chief Financial Officer Office: (315) 299-2946 Community Financial System, Inc. Reports First Quarter 2025 Results SYRACUSE, N.Y. — April 29, 2025 — Community Financial System, Inc. (the “Company”) (NYSE: CBU) reported first quarter 2025 results that are included

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 29, 2025 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employ

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

TABLE OF CONTENTS UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant  ☐ Check the appropriate box:  ☐ Preliminary Proxy Statement  ☐ Confidential, For Use of the Commission Only (as permitted by Rule

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant  ☐ Check the appropriate box:  ☐ Preliminary Proxy Statement  ☐ Confidential, For Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ De

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 11, 2025 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employ

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 COMMUNITY FINANCIAL SYSTEM, INC. APPOINTS MARYA BURGIO WLOS AS EXECUTIVE VICE PRESIDENT AND CHIEF FINANCIAL OFFICER SYRACUSE, N.Y. — March 11, 2025 — Community Financial System, Inc. (the “Company”) (NYSE: CBU) and it

Subsidiaries of Registrant. (1)

Exhibit 21.1 Subsidiaries of Registrant As of December 31, 2024 Name Jurisdiction of Incorporation Benefit Plans Administrative Services, Inc. New York Benefit Plans Administrative Services, LLC New York BPAS Actuarial and Pension Services, LLC New York BPAS Trust Company of Puerto Rico Puerto Rico CBNA Preferred Funding Corp. Delaware CBNA Treasury Management Corporation New York Community Bank,

Community Financial System, Inc. Policy Prohibiting Insider Trading. (1)

Exhibit 19.1 Community Financial System, Inc. Policy Prohibiting Insider Trading Purpose This Policy Prohibiting Insider Trading (the “Policy”) provides guidelines with respect to transactions in the securities of Community Financial System, Inc. (the “Company”) and the handling of confidential information about the Company and the companies with which the Company does business. The Company’s Boar

Description of Community Bank System, Inc.’s securities registered pursuant to Section 12 of the Securities Exchange Act. (1)

Exhibit 4.5 DESCRIPTION OF COMMUNITY FINANCIAL SYSTEM, INC.’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 As of December 31, 2024, Community Financial System, Inc. (the “Company” or “our”) had one class of securities, our common stock, par value $1.00 per share (“Common Stock”), registered under Section 12 of the Securities Exchange Act of 1934, as amended.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-13695 (Exact

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 14, 2025 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Emp

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 21, 2025 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Empl

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Financial System, Inc. Reports Fourth Quarter And Full Year 2024 Results SYRACUSE, N.Y. — January 21, 2025 — Community Financial System, Inc. (the “Company”) (NYSE: CBU) reported fourth quarter and full year

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 18, 2024 (Exact name of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 18, 2024 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Emp

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 7, 2024 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Empl

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-1369

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Financial System, Inc. Reports Third Quarter 2024 Results SYRACUSE, N.Y. — October 22, 2024 — Community Financial System, Inc. (the “Company”) (NYSE: CBU) reported third quarter 2024 results that are include

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 22, 2024 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Empl

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 30, 2024 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Em

Change in Control Agreement, dated January 1, 2024, by and among Deresa F. Durkee, Community Financial System, Inc. and Community Bank, N.A.

Exhibit 10.1 CHANGE OF CONTROL AGREEMENT This CHANGE OF CONTROL AGREEMENT is dated as of January 1, 2024 between COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered bank holding company (“CBSI”), and COMMUNITY BANK, N.A., a wholly-owned subsidiary of CBSI, having an office in DeWitt, New York (“CBNA”) (CBSI and CBNA are referred to collectively in this Agreement as the “Employer”),

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Financial System, Inc. Appoints Savneet Singh as New Independent Director SYRACUSE, N.Y. — September 26, 2024 — Community Financial System, Inc. (the “Company”) (NYSE: CBU) announced today the appointment of

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 25, 2024 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Em

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 4, 2024 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Emp

Investor Day 2024 ‐ ‐ Disclaimers Welcome & Opening Remarks • • • • • Investor Day Agenda Investor Day Speakers Company Overview & Investment Thesis Company Overview • • • • • • • About CBU • • • • • • • • • • • • • • • • How We Operate: Our Core Val

Exhibit 99.1 Investor Day 2024 ‐ ‐ Disclaimers Welcome & Opening Remarks • • • • • Investor Day Agenda Investor Day Speakers Company Overview & Investment Thesis Company Overview • • • • • • • About CBU • • • • • • • • • • • • • • • • How We Operate: Our Core Values Our Evolution Into a Diversified Financial Company • • • • • Our Investment Thesis: • • • • • • Below Average Risk Above Average Retu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-13695 (Ex

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1      News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Financial System, Inc. Reports Second Quarter 2024 Results SYRACUSE, N.Y. — July 23, 2024 — Community Financial System, Inc. (the “Company”) (NYSE: CBU) reported second quarter 2024 results that are inc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 23, 2024 (Exact name of regi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 23, 2024 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employe

Community Financial System, Inc. Code of Business Conduct and Ethics, dated July 17, 2024. Incorporated by reference to Exhibit No. 14.1 to the Current Report on Form 8-K filed on July 19, 2024 (Registration No. 001-13695).

Exhibit 14.1 COMMUNITY FINANCIAL SYSTEM, INC. CODE OF BUSINESS CONDUCT AND ETHICS I.              OVERVIEW This Code of Business Conduct and Ethics (the “Code”) has been adopted by the Board of Directors (the “Board”) of Community Financial System, Inc. (“CFSI”) to establish the guiding principles by which we operate our company and conduct our daily business with our shareholders, current and pot

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Amendment to Registrant's Code of Ethics, or Waiver of a Provision of the Code of Ethics, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 17, 2024 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employe

Community Financial System, Inc. Executive Severance Plan, as amended, July 17, 2024

Exhibit 10.2 COMMUNITY FINANCIAL SYSTEM, INC. EXECUTIVE SEVERANCE PLAN 1.      Purpose. The purpose of this Community Financial System, Inc. (“CFSI”) Executive Severance Plan (“Plan”) is to aid in the retention of certain senior executives of the Company by providing appropriate severance benefits in the event they are terminated in certain circumstances and to ensure their continued dedication to

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 COMMUNITY FINANCIAL SYSTEM, INC. ANNOUNCES INCREASE TO ITS QUARTERLY DIVIDEND RESULTING IN ITS 32nd CONSECUTIVE YEAR OF DIVIDEND INCREASES SYRACUSE, N.Y. — July 17, 2024 — Community Financial System, Inc. (NYSE: CBU)

Amendment to Employment Agreement, dated July 17, 2024, by and among Community Financial System, Inc., Community Bank, N.A., and Dimitar A. Karaivanov. Incorporated by reference to Exhibit No. 10.1 to the Current Report on Form 8-K filed on July 19, 2024 (Registration No. 001-13695). (1)

Exhibit 10.1 AMENDMENT TO EMPLOYMENT AGREEMENT This sets forth the terms of an Amendment to the July 5, 2023 Employment Agreement between (i) COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered bank holding company (“CBSI”), and COMMUNITY BANK, N.A., a national banking association (“CBNA”), both having offices located in Dewitt, New York (collectively, the “Employer”), and (ii) DIMI

As filed with the Securities and Exchange Commission on July 17, 2024

  As filed with the Securities and Exchange Commission on July 17, 2024   Registration No.

Community Financial System, Inc. 2022 Long-Term Incentive Plan, as amended.

EXHIBIT 99.1 COMMUNITY FINANCIAL SYSTEM, INC. 2022 LONG-TERM INCENTIVE PLAN, AS AMENDED Table of Contents Establishment 1 Purpose 1 Eligibility 1 Definitions 1 Shares Available Under the Plan 4 Grants of Option Rights Generally 5 Special Rules for Grants of Incentive Stock Options 6 Special Rules for Grants of Nonqualified Stock Options 7 Stock Appreciation Rights 7 Restricted Stock Awards 8 Restr

Filing fee table

EXHIBIT 107 Calculation of Filing Fee Tables FORM S-8 (Form Type) Community FINANCIAL System, Inc.

Community Financial System, Inc. Deferred Compensation Plan for Directors, amended and restated.

EXHIBIT 99.1 COMMUNITY FINANCIAL SYSTEM, INC. DEFERRED COMPENSATION PLAN FOR DIRECTORS Amended and Restated as of May 15, 2024 ARTICLE I PURPOSE AND DEFINITIONS Section 1.01 – Purpose: The Company’s Board of Directors adopted the Community Financial System, Inc. Deferred Compensation Plan for Directors, effective as of January 19, 1994, to provide a uniform mechanism for the elective deferral by m

As filed with the Securities and Exchange Commission on July 17, 2024

As filed with the Securities and Exchange Commission on July 17, 2024 Registration No.

Filing fee table

EXHIBIT 107 Calculation of Filing Fee Tables FORM S-8 (Form Type) Community FINANCIAL System, Inc.

United States SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K

United States SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 ¨ TRANSITION REPORT PURSUANT TO SECTION 15 (d) OF THE SECURITIES AND EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 001-13695 A. Full title of the plan

Financial Statements and Exhibits, Other Events, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 15, 2024 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer

Consulting Agreement, dated May 15, 2024, by and among Community Financial System, Inc., Community Bank, N.A., and Mark E. Tryniski

Exhibit 10.1 CONSULTING AGREEMENT This Consulting Agreement (the “Agreement”), dated as of May 15, 2024, is between Community Financial System, Inc., a Delaware corporation and registered bank holding company (“CFSI”) and Community Bank, N.A., a national bank holding association (“CBNA”), both having offices located in Dewitt, New York (collectively, the “Company”) and Mark E. Tryniski, an individ

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Financial System, Inc. Announces Quarterly Common Stock Dividend and Results of Annual Shareholders’ Meeting SYRACUSE, N.Y. — May 15, 2024 — Community Financial System, Inc. (NYSE: CBU) (the “Company”) annou

Community Bank System, Inc. Changes Corporate Name to Community Financial System, Inc. New corporate name reflects the Company’s broader business model and mission in contributing to the prosperity of its community, including its clients, colleagues

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Changes Corporate Name to Community Financial System, Inc. New corporate name reflects the Company’s broader business model and mission in contributing to the prosperity of its community, i

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 15, 2024 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identification

Amended and Restated Certificate of Incorporation, filed with the Delaware Secretary of State on May 15, 2024. Incorporated by reference to Exhibit No. 3.1 to the Current Report on Form 8-K filed on May 16, 2024 (Registration No. 001-13695).

Exhibit 3.1 AMENDED & RESTATED CERTIFICATE OF INCORPORATION Community Bank System, Inc., a Delaware corporation, hereby certifies as follows. 1. The name of the corporation is Community Bank System, Inc. The date of filing its original Certificate of Incorporation with the Secretary of State was April 15, 1983, under the name Community Bank System, Inc. 2. The Amended & Restated Certificate of Inc

Amended and Restate Bylaws of Community Financial System, Inc., as of May 15, 2024. Incorporated by reference to Exhibit No. 3.2 to the Current Report on Form 8-K filed on May 16, 2024 (Registration No. 001-13695).

Exhibit 3.2 Community Financial System, Inc. Bylaws COMMUNITY FINANCIAL SYSTEM, INC. BYLAWS Community Financial System, Inc. Bylaws COMMUNITY FINANCIAL SYSTEM, INC. BYLAWS ARTICLE 1 Stockholders 1 1.1 Place of Meeting 1 1.2 Annual Meeting 1 1.3 Business at Annual Meeting 1 1.4 Special Meetings 2 1.5 Fixing Record Date 2 1.6 Notice of Meetings of Stockholders 3 1.7 Waivers of Notice 4 1.8 List of S

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-13695 (E

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Reports First Quarter 2024 Results SYRACUSE, N.Y. — April 23, 2024 — Community Bank System, Inc. (the “Company”) (NYSE: CBU) reported first quarter 2024 results that are included in the att

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 23, 2024 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificati

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

TABLE OF CONTENTS UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant  ☐ Check the appropriate box:  ☐ Preliminary Proxy Statement  ☐ Confidential, For Use of the Commission Only (as permitted by Rule

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant  ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, For Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Defi

Description of Community Bank System, Inc.’s securities registered pursuant to Section 12 of the Securities Exchange Act. (1)

Exhibit 4.5 DESCRIPTION OF COMMUNITY BANK SYSTEM, INC.’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 As of December 31, 2023, Community Bank System, Inc. (the “Company” or “our”) had one class of securities, our common stock, par value $1.00 per share (“Common Stock”), registered under Section 12 of the Securities Exchange Act of 1934, as amended. The Common

Policy for the Recovery of Erroneously Awarded Compensation (1)

Exhibit 97.1 COMMUNITY BANK SYSTEM, INC. Policy for the Recovery of Erroneously Awarded Compensation INTRODUCTION The Board of Directors (the “Board”) of Community Bank System, Inc. (the “Company”) has adopted this Policy for the Recovery of Erroneously Awarded Compensation (the “Policy”) to provide for the recovery of erroneously awarded Incentive-based Compensation from Executive Officers. This

o UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents o UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

Subsidiaries of Registrant. (1)

Exhibit 21.1 Subsidiaries of Registrant As of December 31, 2023 Name Jurisdiction of Incorporation Benefit Plans Administrative Services, Inc. New York Benefit Plans Administrative Services, LLC New York BPAS Actuarial and Pension Services, LLC New York BPAS Trust Company of Puerto Rico Puerto Rico CBNA Preferred Funding Corp. Delaware CBNA Treasury Management Corporation New York Community Bank,

CBU / Community Bank System, Inc. / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SC 13G/A 1 tv0656-communitybanksystemin.htm SCHEDULE 13G/A SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 15)* Name of issuer: Community Bank System Inc Title of Class of Securities: Common Stock CUSIP Number: 203607106 Date of Event Which Requires Filing of this Statement: December 29, 2023 Check the appropriate box

CBU / Community Bank System, Inc. / Neuberger Berman Group LLC Passive Investment

SC 13G 1 formsc13g-02122024070256.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 COMMUNITY BANK SYSTEM, INC. (Name of Issuer) Common (Title of Class of Securities) 203607106 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursu

Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 23, 2024 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Reports Fourth Quarter And Full Year 2023 Results SYRACUSE, N.Y. — January 23, 2024 — Community Bank System, Inc. (the “Company”) (NYSE: CBU) reported fourth quarter and full year 2023 resu

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 23, 2024 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identifica

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 19, 2024 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identifica

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Elects Michele Sullivan as New Independent Director SYRACUSE, N.Y. — January 19, 2024 — Community Bank System, Inc. (NYSE: CBU) (the “Company”) announced today the election of Michele Sulli

January 10, 2024

January 10, 2024 Mr. Sarmad Makhdoom U.S. Securities and Exchange Commission (“SEC”) Division of Corporation Finance 100 F Street, NE Washington D.C. 20549 Ref: Community Bank System, Inc. (“Company”) Comment Letter (File No. 001-13695) Dear Mr. Makhdoom: We are in receipt of the above Comment Letter dated December 26, 2023 regarding the Company’s Form 10-K for the Fiscal Year Ended December 31, 2

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 31, 2023 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identific

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 20, 2023 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identific

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-1369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 24, 2023 (Exact name of r

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 24, 2023 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identifica

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Reports Third Quarter 2023 Results SYRACUSE, N.Y. — October 24, 2023 — Community Bank System, Inc. (the “Company”) (NYSE: CBU) reported third quarter 2023 results that are included in the a

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission File Number: 001-13695 (

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Reports Second Quarter 2023 Results SYRACUSE, N.Y. — July 31, 2023 — Community Bank System, Inc. (the “Company”) (NYSE: CBU) reported second quarter 2023 results that are included in the at

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 31, 2023 (Exact name of regi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 31, 2023 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificatio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 18, 2023 (Exact name of regi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 18, 2023 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificatio

Community Bank System, Inc. Executive Severance Plan, dated July 18, 2023

Exhibit 10.1 COMMUNITY BANK SYSTEM, INC. EXECUTIVE SEVERANCE PLAN 1. Purpose. The purpose of this Community Bank System, Inc. (“CBSI”) Executive Severance Plan (“Plan”) is to aid in the retention of certain senior executives of the Company by providing appropriate severance benefits in the event they are terminated in certain circumstances and to ensure their continued dedication to their duties i

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Announces CEO Succession Plan SYRACUSE, N.Y. — July 5, 2023 — Community Bank System, Inc. (NYSE: CBU) (the “Company”) today announced that Mark E. Tryniski will retire as the Company’s Pres

Employment Agreement, dated July 5, 2023, by and among Community Bank System, Inc., Community Bank, N.A., and Dimitar Karaivanov. Incorporated by reference to Exhibit No. 10.1 to the Current Report on Form 8-K filed on July 5, 2023 (Registration No. 001-13695). (2)

Exhibit 10.1 EMPLOYMENT AGREEMENT This sets forth the terms of the Employment Agreement made as of July 5, 2023 between (i) COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered financial holding company (“CBSI”), and COMMUNITY BANK, N.A., a national banking association (“CBNA”), both having offices in DeWitt, New York (collectively, the “Employer”), and (ii) DIMITAR KARAIVANOV, an in

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 5, 2023 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identification

United States SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K

United States SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 ¨ TRANSITION REPORT PURSUANT TO SECTION 15 (d) OF THE SECURITIES AND EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 001-13695 A. Full title of the plan

Financial Statements and Exhibits, Other Events, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 17, 2023 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identification

Community Bank System, Inc. Announces Quarterly Common Stock Dividend and Results of Annual Shareholders’ Meeting

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Announces Quarterly Common Stock Dividend and Results of Annual Shareholders’ Meeting SYRACUSE, N.Y. — May 17, 2023 — Community Bank System, Inc. (NYSE: CBU) (the “Company”) announced that

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission File Number: 001-13695

Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Reports First Quarter 2023 Results SYRACUSE, N.Y. — April 25, 2023 — Community Bank System, Inc. (the “Company”) (NYSE: CBU) reported first quarter 2023 net income of $5.8 million, or $0.11

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 25, 2023 (Exact name of reg

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 25, 2023 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificati

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant  ☐ Check the appropriate box:  ☐ Preliminary Proxy Statement  ☐ Confidential, For Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ De

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

TABLE OF CONTENTS UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant  ☐ Check the appropriate box:  ☐ Preliminary Proxy Statement  ☐ Confidential, For Use of the Commission Only (as permitted by Rule

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-13695 (Exact

Subsidiaries of Registrant. (1)

Exhibit 21.1 Subsidiaries of Registrant As of December 31, 2022 Name Jurisdiction of Incorporation Benefit Plans Administrative Services, Inc. New York Benefit Plans Administrative Services, LLC New York BPAS Actuarial and Pension Services, LLC New York BPAS Trust Company of Puerto Rico Puerto Rico CBNA Preferred Funding Corp. Delaware CBNA Treasury Management Corporation New York Community Bank,

Description of Community Bank System, Inc.’s securities registered pursuant to Section 12 of the Securities Exchange Act. (1)

Exhibit 4.5 DESCRIPTION OF COMMUNITY BANK SYSTEM, INC.’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 As of December 31, 2022, Community Bank System, Inc. (the “Company” or “our”) had one class of securities, our common stock, par value $1.00 per share (“Common Stock”), registered under Section 12 of the Securities Exchange Act of 1934, as amended. The Common

CBU / Community Bank System, Inc. / Neuberger Berman Group LLC - NONE Passive Investment

SC 13G/A 1 doc1.htm NONE UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* COMMUNITY BANK SYSTEM, INC. (Name of Issuer) Common (Title of Class of Securities) 203607106 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule

CBU / Community Bank System, Inc. / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SC 13G/A 1 tv0632-communitybanksystemin.htm SCHEDULE 13G/A SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 14)* Name of issuer: Community Bank System Inc. Title of Class of Securities: Common Stock CUSIP Number: 203607106 Date of Event Which Requires Filing of this Statement: December 30, 2022 Check the appropriate bo

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 1, 2023 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identifica

Community Bank System, Inc. Announces Balance Sheet Repositioning

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Announces Balance Sheet Repositioning SYRACUSE, N.Y. — February 1, 2023 — Community Bank System, Inc. (NYSE: CBU) (the “Company”) announced today the completion of a balance sheet repositio

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Reports Fourth Quarter And Full Year 2022 Results SYRACUSE, N.Y. — January 24, 2023 — Community Bank System, Inc. (the “Company”) (NYSE: CBU) reported fourth quarter 2022 net income of $52.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 24, 2023 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identifica

Amended and Restated Bylaws, dated December 14, 2022. Incorporated by reference to Exhibit No. 3.2 to the Current Report on Form 8-K filed on December 19, 2022 (Registration No. 001-13695)

Exhibit 3.2 Amended and Restated Bylaws of Community Bank System, Inc., dated as of December 14, 2022 Community Bank System, Inc. ?Bylaws COMMUNITY BANK SYSTEM, INC. BYLAWS Community Bank System, Inc. ?Bylaws COMMUNITY BANK SYSTEM, INC. BYLAWS ARTICLE 1 Stockholders 1 1.1 Place of Meeting 1 1.2 Annual Meeting 1 1.3 Business at Annual Meeting 1 1.4 Other Special Meetings 2 1.5 Fixing Record Date 2

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 14, 2022 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identific

3.1 Marked to show revisions to Section 2.18 of Amended and Restated Bylaws of Community Bank System, Inc., dated as of December 14, 2022

Exhibit 3.1 Marked to show revisions to Section 2.18 of Amended and Restated Bylaws of Community Bank System, Inc., dated as of December 14, 2022 Effective as of December 14, 2022, Section 2.18 of the Amended and Restated Bylaws of Community Bank System, Inc. was amended as marked: 2.18 Term of Office. The term of a Director shall terminate at December 31 the next annual Stockholders' meeting foll

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission File Number: 001-13

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

EX-99.1 2 tm2228760d1ex99-1.htm EXHIBIT 99.1 Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Reports Third Quarter 2022 Results SYRACUSE, N.Y. — October 24, 2022 — Community Bank System, Inc. (NYSE: CBU) reported third quarter 2022 net i

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 24, 2022 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Empl

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Announces Senior Management Changes SYRACUSE, N.Y. ? August 25, 2022 ? Community Bank System, Inc. (NYSE: CBU) (the ?Company?) announced two senior management changes. Joseph F. Serbun, Pre

 Amendment to Employment Agreement, effective August 24, 2022, by and among Community Bank System, Inc., Community Bank, N.A., and Dimitar Karaivanov

Exhibit 10.1 AMENDMENT TO EMPLOYMENT AGREEMENT This sets forth the terms of an Amendment to the March 22, 2021 Employment Agreement between (i) COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered bank holding company (?CBSI?), and COMMUNITY BANK, N.A., a national banking association (?CBNA?), both having offices located in Dewitt, New York (collectively, the ?Employer?), and (ii) DI

 Retirement Agreement, dated August 24, 2022, by and among Community Bank System, Inc., Community Bank, N.A. and Joseph F. Serbun

Exhibit 10.2 RETIREMENT AGREEMENT THIS RETIREMENT AGREEMENT (this ?Agreement?) is made by and among JOSEPH F. SERBUN (?Employee?), COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered bank holding company (?CBSI?), and COMMUNITY BANK, N.A., a national banking association (?CBNA,? and together with CBSI, the ?Company?), dated as of August 24, 2022 (the ?Signing Date?). WHEREAS, the Co

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 24, 2022 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Emplo

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents ? ? UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Reports Second Quarter 2022 Results SYRACUSE, N.Y. ? July 25, 2022 ? Community Bank System, Inc. (NYSE: CBU) reported second quarter 2022 net income of $39.8 million, or $0.73 per fully-dil

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 25, 2022 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employe

Filing fee table

EXHIBIT 107 Calculation of Filing Fee Tables FORM S-8 (Form Type) Community Bank System, Inc.

As filed with the Securities and Exchange Commission on July 20, 2022

As filed with the Securities and Exchange Commission on July 20, 2022 Registration No.

As filed with the Securities and Exchange Commission on July 20, 2022

As filed with the Securities and Exchange Commission on July 20, 2022 Registration No.

United States SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K

United States SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 ? TRANSITION REPORT PURSUANT TO SECTION 15 (d) OF THE SECURITIES AND EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 001-13695 A. Full title of the plan

Financial Statements and Exhibits, Other Events, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 18, 2022 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identification

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Announces Quarterly Common Stock Dividend and Results of Annual Shareholders? Meeting SYRACUSE, N.Y. ? May 18, 2022 ? Community Bank System, Inc. (NYSE: CBU) (the ?Company?) announced that

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 13, 2022 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction (Commission (IRS Employer of incorporation) File Number)

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank, N.A. Completes Merger with Elmira Savings Bank and Expands Its Presence in the Central New York and Southern Tier Regions SYRACUSE, N.Y. ? May 16, 2022 ?Community Bank System, Inc. (?Community Bank Sys

Employment Agreement, dated March 22, 2021, by and among Community Bank System, Inc., Community Bank, N.A. and Dimitar Karaivanov. (1)(2)

Exhibit 10.2 ? EMPLOYMENT AGREEMENT ? This sets forth the terms of the Employment Agreement between (i) COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered financial holding company (?CBSI?), and COMMUNITY BANK, N.A., a national banking association (?CBNA?), both having offices located in Dewitt, New York (collectively, the ?Employer?), and (ii) DIMITAR KARAIVANOV (?Employee?). This

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents ? ? UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

Community Bank System, Inc. 2022 Long-Term Incentive Plan, as amended. Incorporated by reference to Exhibit No. 10.1 to the Current Report on Form 8-K filed on May 6, 2022 (Registration No. 001-13695). (2)

Exhibit 10.1 COMMUNITY BANK SYSTEM, INC. 2022 LONG-TERM INCENTIVE PLAN, AS AMENDED Table of Contents Establishment 1 Purpose 1 Eligibility 1 Definitions 1 Shares Available Under the Plan 4 Grants of Option Rights Generally 5 Special Rules for Grants of Incentive Stock Options 6 Special Rules for Grants of Nonqualified Stock Options 7 Stock Appreciation Rights 7 Restricted Stock Awards 8 Restricted

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 5, 2022 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identification

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. 1)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. 1) Filed by the Registrant x Filed by a Party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, For Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Defi

Amendment to Employment Agreement, dated April 28, 2022, by and among Community Bank System, Inc., Community Bank, N.A. and George J. Getman.

Exhibit 10.1 AMENDMENT TO EMPLOYMENT AGREEMENT This sets forth the terms of an Amendment to the January 1, 2020 Employment Agreement between (i) COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered bank holding company (?CBSI?), and COMMUNITY BANK, N.A., a national banking association (?CBNA?), both having offices located in Dewitt, New York (collectively, the ?Employer?), and (ii) G

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 28, 2022 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificati

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 25, 2022 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificati

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Reports First Quarter 2022 Results SYRACUSE, N.Y. ? April 25, 2022 ? Community Bank System, Inc. (NYSE: CBU) reported first quarter 2022 net income of $47.1 million, or $0.86 per fully-dilu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

TABLE OF CONTENTS UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant  ☐ Check the appropriate box:  ☐ Preliminary Proxy Statement  ☐ Confidential, For Use of the Commission Only (as permitted by Rule

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, For Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Defin

Subsidiaries of Registrant. (1)

Exhibit 21.1 Subsidiaries of Registrant As of December 31, 2021 ? ? Name Jurisdiction of Incorporation Benefit Plans Administrative Services, Inc. New York Benefit Plans Administrative Services, LLC New York BPAS Actuarial and Pension Services, LLC New York BPAS Trust Company of Puerto Rico Puerto Rico CBNA Preferred Funding Corp. Delaware CBNA Treasury Management Corporation New York Community Ba

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents ? ? UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

Description of Community Bank System, Inc.’s securities registered pursuant to Section 12 of the Securities Exchange Act.

Exhibit 4.5 DESCRIPTION OF COMMUNITY BANK SYSTEM, INC.?S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 As of December 31, 2021, Community Bank System, Inc. (the ?Company? or ?our?) had one class of securities, our common stock, par value $1.00 per share (?Common Stock?), registered under Section 12 of the Securities Exchange Act of 1934, as amended. The Common

CBU / Community Bank System, Inc. / Neuberger Berman Group LLC - NONE Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. n/a )* COMMUNITY BANK SYSTEM, INC. (Name of Issuer) Common (Title of Class of Securities) 203607106 (CUSIP Number) December 31, 2021 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which thi

CBU / Community Bank System, Inc. / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 13)* Name of issuer: Community Bank System Inc. Title of Class of Securities: Common Stock CUSIP Number: 203607106 Date of Event Which Requires Filing of this Statement: December 31, 2021 Check the appropriate box to designate the rule pursuant to which this Schedule is

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 24, 2022 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identifica

Office: (315) 445-7396

Exhibit 99-1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 6, 2022 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificat

Employment Agreement, dated as of January 5, 2022, by and among Community Bank System, Inc., Community Bank N.A., and Joseph F. Serbun. Incorporated by reference to Exhibit No. 10.1 to the Current Report on Form 8-K filed on January 6, 2022 (Registration No. 001-13695). (2)

Exhibit 10.1 EMPLOYMENT AGREEMENT This sets forth the terms of the Employment Agreement made as of January 1, 2022 between (i) COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered bank holding company (?CBSI?), and COMMUNITY BANK, N.A., a national banking association (?CBNA?), both having offices located in Dewitt, New York (collectively, the ?Employer?), and (ii) JOSEPH F. SERBUN, a

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Appoints Jeff Knauss as New Independent Director SYRACUSE, N.Y. ? December 16, 2021 ? Community Bank System, Inc. (NYSE: CBU) (the ?Company?) announced today the appointment of Jeffery Knau

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 16, 2021 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identific

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents ? ? UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Reports Third Quarter 2021 Results SYRACUSE, N.Y. ? October 25, 2021 ? Community Bank System, Inc. (NYSE: CBU) (the ?Company?) reported third quarter 2021 net income of $45.3 million, or $0

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 25, 2021 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identifica

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 3, 2021 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificat

Agreement and Plan of Merger, dated as of October 3, 2021, by and between Community Bank, N.A., Eagle Merger Sub Inc. and Elmira Savings Bank. Incorporated by reference to Exhibit 2.1 to the Current Report on Form 8-K filed on October 7, 2021 (Registration No. 001-13695).

Exhibit 2.1 Execution Version AGREEMENT AND PLAN OF MERGER BY AND AMONG COMMUNITY BANK, N.A., EAGLE MERGER SUB INC. AND ELMIRA SAVINGS BANK Dated as of October 3, 2021 TABLE OF CONTENTS Page Article 1 Transactions and Terms of Merger Section 1.1 First Step Merger 2 Section 1.2 Second Step Merger 3 Section 1.3 Structure Change 3 Article 2 Treatment of Securities Section 2.1 Treatment of Elmira Shar

Community Bank System, Inc. to Expand Its Presence in the Central New York and Southern Tier Regions with Acquisition of Elmira Savings Bank

Exhibit 99.1 Community Bank System, Inc. to Expand Its Presence in the Central New York and Southern Tier Regions with Acquisition of Elmira Savings Bank October 4, 2021 SYRACUSE, NY and ELMIRA, NY?(BUSINESS WIRE) ?Community Bank System, Inc. (?Community Bank System?) (NYSE: CBU) and Elmira Savings Bank (NASDAQ-CM: ESBK) today announced that they have entered into a definitive agreement pursuant t

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 4, 2021 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificat

OCTOBER 2021 ACQUISITION OF ELMIRA SAVINGS BANK CBU LISTED NYSE

EX-99.2 3 tm2129141d1ex99-2.htm EXHIBIT 99.2 Exhibit 99.2 OCTOBER 2021 ACQUISITION OF ELMIRA SAVINGS BANK CBU LISTED NYSE This presentation contains certain “forward - looking statements” within the meaning of the Private Securities Litigation Reform A ct of 1995, including statements about Community Bank System’s long - term goals, financial condition, results of operations, earnings, levels of n

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Appoints Maureen Gillan-Myer as Executive Vice President and Chief Human Resources Officer SYRACUSE, N.Y. ? September 2, 2021 ? Community Bank System, Inc. (NYSE: CBU) (the ?Company?) is pl

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 2, 2021 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identific

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents ? ? UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: Joseph E. Sutaris, EVP & Chief Financial Officer 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Office: (315) 445-7396 Community Bank System Reports Second Quarter 2021 Results SYRACUSE, N.Y. ? July 26, 2021 ? Community Bank System, Inc. (NYSE: CBU) reported second quarter 2021 net income of $47.9 million, or $0.88 per fully-diluted s

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 26, 2021 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificatio

United States SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K

United States SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2020 ? TRANSITION REPORT PURSUANT TO SECTION 15 (d) OF THE SECURITIES AND EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 001-13695 A. Full title of the plan

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Announces Quarterly Common Stock Dividend and Results of Annual Shareholders? Meeting SYRACUSE, N.Y. ? May 13, 2021 ? Community Bank System, Inc. (NYSE: CBU) (the ?Company?) announced that

Financial Statements and Exhibits, Other Events, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 13, 2021 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction (Commission (IRS Employer of incorporation) File Number)

Employment Agreement, dated December 29, 2020, by and among Community Bank System, Inc., Community Bank, N.A. and Joseph J. Lemchak. (1)(2)

Exhibit 10.3 ? EMPLOYMENT AGREEMENT This sets forth the terms of the Employment Agreement made executed on December 29, 2020, between (i) COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered bank holding company (?CBSI?), and COMMUNITY BANK, N.A., a national banking association (?CBNA?), both having offices located in Dewitt, New York (collectively, the ?Employer?), and (ii) JOSEPH J

Quarterly Report - FORM 10-Q

Table of Contents ? ? UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 26, 2021 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificati

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System Reports First Quarter 2021 Results SYRACUSE, N.Y. ? April 26, 2021 ? Community Bank System, Inc. (NYSE: CBU) reported first quarter 2021 net income of $52.9 million, or $0.97 per fully-diluted sh

Mark E. Tryniski, President & CEO Office: (315) 445-7378

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Mark E. Tryniski, President & CEO Office: (315) 445-7378 Community Bank System, Inc. Appoints Dimitar Karaivanov as Executive Vice President of Financial Services and Corporate Development SYRACUSE, N.Y. ? March 29, 2021 ? Community Bank System, Inc. (NYSE: CBU) (the ?Company?) is pleased

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 29, 2021 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction (Commission File Number) (IRS Employer Identification

- DEF 14A

DEF 14A 1 nc10018663x1def14a.htm DEF 14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, For Use of the Commission Only (

- DEFA14A

DEFA14A 1 nc10018663x2defa14a.htm DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, For Use of the Commission Only

Subsidiaries of Registrant. (1)

Exhibit 21.1 ? Subsidiaries of Registrant As of December 31, 2020 ? ? ? Name Jurisdiction of Incorporation Benefit Plans Administrative Services, Inc. New York Benefit Plans Administrative Services, LLC New York BPAS Actuarial and Pension Services, LLC New York BPAS Trust Company of Puerto Rico Puerto Rico CBNA Preferred Funding Corp. Delaware CBNA Treasury Management Corporation New York Communit

Annual Report - 10-K

Table of Contents ma ? UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

Description of Community Bank System, Inc.’s securities registered pursuant to Section 12 of the Securities Exchange Act.

Exhibit 4.5 ? DESCRIPTION OF COMMUNITY BANK SYSTEM, INC.?S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 As of December 31, 2020, Community Bank System, Inc. (the ?Company? or ?our?) had one class of securities, our common stock, par value $1.00 per share (?Common Stock?), registered under Section 12 of the Securities Exchange Act of 1934, as amended. The Comm

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 12)*

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 12)* Name of issuer: Community Bank System Inc. Title of Class of Securities: Common Stock CUSIP Number: 203607106 Date of Event Which Requires Filing of this Statement: December 31, 2020 Check the appropriate box to designate the rule pursuant to which this Schedule is

0 Q4 2020 EARNINGS RELEASE SUPPLEMENTAL INFORMATION

Exhibit 99.2 0 Q4 2020 EARNINGS RELEASE SUPPLEMENTAL INFORMATION 1 This presentation contains forward - looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements are based on the current beliefs and expectations of CBU’s management and are subject to significant risks and uncertainties. Actual results may differ from those set forth in the forw

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 25, 2021 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identifica

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System Reports Fourth Quarter and Full Year 2020 Results SYRACUSE, N.Y. — January 25, 2021 — Community Bank System, Inc. (NYSE: CBU) reported fourth quarter 2020 net income of $46.5 million, or $0.86 pe

Employment Agreement, dated as of January 4, 2021, by and between Community Bank System, Inc., Community Bank, N.A., and Joseph E. Sutaris. Incorporated by reference to Exhibit No. 10.2 to the Current Report on Form 8-K filed on January 6, 2021 (Registration No. 001-13695). (2)

Exhibit 10.2 EMPLOYMENT AGREEMENT This sets forth the terms of the Employment Agreement between (i) COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered bank holding company (“CBSI”), and COMMUNITY BANK, N.A., a national banking association (“CBNA”), both having offices located in Dewitt, New York (collectively, the “Employer”), and (ii) JOSEPH E. SUTARIS, an individual currently res

Employment Agreement, dated as of January 4, 2021, by and between Community Bank System, Inc., Community Bank, N.A., and Mark E. Tryniski. Incorporated by reference to Exhibit No. 10.1 to the Current Report on Form 8-K filed on January 6, 2021 (Registration No. 001-13695). (2)

EX-10.1 2 tm211827d1ex10-1.htm EXHIBIT 10.1 Exhibit 10.1 EMPLOYMENT AGREEMENT This sets forth the terms of the Employment Agreement made as of January 1, 2021 between (i) COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered bank holding company (“CBSI”), and COMMUNITY BANK, N.A., a national banking association (“CBNA”), both having offices in DeWitt, New York (collectively, the “Empl

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events - FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 31, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identific

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits - FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 18, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identific

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Elects Susan E. Skerritt as New Independent Director SYRACUSE, N.Y. — November 19, 2020 — Community Bank System, Inc. (NYSE: CBU) (the “Company”) announced today the election of Susan E. Sk

NOVEMBER 16, 2020 COVID - 19 LOAN DEFERRAL UPDATE SUPPLEMENTAL INFORMATION

Exhibit 99.1 NOVEMBER 16, 2020 COVID - 19 LOAN DEFERRAL UPDATE SUPPLEMENTAL INFORMATION This presentation contains comments or information that constitute forward - looking statements (within the meaning of the Private Securities Litigation Refo rm Act of 1995), which involve significant risks and uncertainties. Forward - looking statements often use words such as “anticipate,” “could,” “target, ”

Regulation FD Disclosure, Financial Statements and Exhibits - FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 16, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identific

Quarterly Report - FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ⌧ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2020 OR ◻ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission File Number: 001-13

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System Reports Third Quarter 2020 Results and COVID-19 Pandemic Update SYRACUSE, N.Y. — October 26, 2020 — Community Bank System, Inc. (NYSE: CBU) reported third quarter 2020 net income of $42.8 million

Financial Statements and Exhibits, Results of Operations and Financial Condition - FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 26, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identifica

0 Q3 2020 EARNINGS RELEASE SUPPLEMENTAL INFORMATION

Exhibit 99.2 0 Q3 2020 EARNINGS RELEASE SUPPLEMENTAL INFORMATION 1 This presentation contains forward - looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements are based on the current beliefs and expectations of CBU’s management and are subject to significant risks and uncertainties. Actual results may differ from those set forth in the forw

Regulation FD Disclosure - FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 9, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identific

Quarterly Report - 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 001-13695 (Exact name of registr

0 Q2 2020 EARNINGS RELEASE SUPPLEMENTAL INFORMATION

Exhibit 99.2 0 Q2 2020 EARNINGS RELEASE SUPPLEMENTAL INFORMATION 1 This presentation contains forward - looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements are based on the current beliefs and expectations of CBU’s management and are subject to significant risks and uncertainties. Actual results may differ from those set forth in the forw

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System Reports Second Quarter 2020 Results and COVID-19 Pandemic Update SYRACUSE, N.Y. — July 27, 2020 — Community Bank System, Inc. (NYSE: CBU) reported second quarter 2020 net income of $35.2 million,

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 27, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employe

- FORM 11-K

11-K 1 tm2023485d111k.htm FORM 11-K United States SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2019 ¨ TRANSITION REPORT PURSUANT TO SECTION 15 (d) OF THE SECURITIES AND EXCHANGE ACT OF 1934 For the transition period from to Commission File Number

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Completes Merger with Steuben Trust Corporation and Enhances Western New York Presence SYRACUSE, N.Y. — June 15, 2020 —Community Bank System, Inc. (“Community Bank System”) (NYSE: CBU), the

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 12, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificatio

CERTIFICATE OF AMENDMENT OF THE CERTIFICATE OF INCORPORATION COMMUNITY BANK SYSTEM, INC. Pursuant to Section 242 of the General Corporation Law of the State of Delaware

Exhibit 3.2 Certificate of Amendment to the Certificate of Incorporation CERTIFICATE OF AMENDMENT OF THE CERTIFICATE OF INCORPORATION OF COMMUNITY BANK SYSTEM, INC. Pursuant to Section 242 of the General Corporation Law of the State of Delaware FIRST: COMMUNITY BANK SYSTEM, INC. (the “Corporation”) is a corporation formed under the laws of the State of Delaware. Its Certificate of Incorporation wa

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits, Other Events, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 20, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identification

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Announces Quarterly Common Stock Dividend and Results of Annual Shareholders Meeting SYRACUSE, N.Y. — May 20, 2020 — Community Bank System, Inc. (NYSE: CBU) (the “Company”) announced that i

Certificate of Amendment to the Certificate of Incorporation, dated May 20, 2020. Incorporated by reference to Exhibit No. 3.2 to the Current Report on Form 8-K filed on May 22, 2020 (Registration No. 001-13695).

Exhibit 3.2 Certificate of Amendment to the Certificate of Incorporation CERTIFICATE OF AMENDMENT OF THE CERTIFICATE OF INCORPORATION OF COMMUNITY BANK SYSTEM, INC. Pursuant to Section 242 of the General Corporation Law of the State of Delaware FIRST: COMMUNITY BANK SYSTEM, INC. (the “Corporation”) is a corporation formed under the laws of the State of Delaware. Its Certificate of Incorporation wa

Merger Prospectus - 425

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 20, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identification

Bylaws, dated May 20, 2020. Incorporated by reference to Exhibit No. 3.1 to the Current Report on Form 8-K filed on May 22, 2020 (Registration No. 001-13695)

Exhibit 3.1 Community Bank System, Inc. Bylaws COMMUNITY BANK SYSTEM, INC. BYLAWS Community Bank System, Inc. Bylaws COMMUNITY BANK SYSTEM, INC. BYLAWS ARTICLE 1 Stockholders 1 1.1 Place of Meeting 1 1.2 Annual Meeting 1 1.3 Business at Annual Meeting 1 1.4 Other Special Meetings. 2 1.5 Fixing Record Date. 2 1.6 Notice of Meetings of Stockholders. 3 1.7 Waivers of Notice. 4 1.8 List of Stockholder

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Announces Quarterly Common Stock Dividend and Results of Annual Shareholders Meeting SYRACUSE, N.Y. — May 20, 2020 — Community Bank System, Inc. (NYSE: CBU) (the “Company”) announced that i

COMMUNITY BANK SYSTEM, INC.

Exhibit 3.1 Community Bank System, Inc. Bylaws COMMUNITY BANK SYSTEM, INC. BYLAWS Community Bank System, Inc. Bylaws COMMUNITY BANK SYSTEM, INC. BYLAWS ARTICLE 1 Stockholders 1 1.1 Place of Meeting 1 1.2 Annual Meeting 1 1.3 Business at Annual Meeting 1 1.4 Other Special Meetings. 2 1.5 Fixing Record Date. 2 1.6 Notice of Meetings of Stockholders. 3 1.7 Waivers of Notice. 4 1.8 List of Stockholder

0 Annual Meeting of Shareholders Company Performance Summary May 20, 2020 1 FORWARD - LOOKING STATEMENT This presentation contains forward - looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statemen

Exhibit 99.1 0 Annual Meeting of Shareholders Company Performance Summary May 20, 2020 1 FORWARD - LOOKING STATEMENT This presentation contains forward - looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements are based on the current beliefs and expectations of CBU’s management and are subject to significant risks and uncertainties. Actual r

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 19, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identification

Merger Prospectus - 425

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 19, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction (Commission File Number) (IRS Employer Identification of

0 Annual Meeting of Shareholders Company Performance Summary May 20, 2020 1 FORWARD - LOOKING STATEMENT This presentation contains forward - looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statemen

Exhibit 99.1 0 Annual Meeting of Shareholders Company Performance Summary May 20, 2020 1 FORWARD - LOOKING STATEMENT This presentation contains forward - looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements are based on the current beliefs and expectations of CBU’s management and are subject to significant risks and uncertainties. Actual r

Merger Prospectus - 425

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 13, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identification

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 13, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identification

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Announces Regulatory Approvals Received for Merger with Steuben Trust Corporation SYRACUSE, N.Y. — May 13, 2020 — Community Bank System, Inc. (NYSE: CBU) (the “Company”) announced that it h

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Announces Regulatory Approvals Received for Merger with Steuben Trust Corporation SYRACUSE, N.Y. — May 13, 2020 — Community Bank System, Inc. (NYSE: CBU) (the “Company”) announced that it h

Quarterly Report - 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 001-13695 (Exact name of regist

- DEFA14A

DEFA14A 1 tm2018108-1defa14a.htm DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commi

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System Reports First Quarter 2020 Results and COVID-19 Pandemic Response SYRACUSE, N.Y. — April 20, 2020 — Community Bank System, Inc. (NYSE: CBU) reported first quarter 2020 net income of $40.1 million

APRIL 2020 COVID - 19 PANDEMIC RESPONSE

Exhibit 99.2 APRIL 2020 COVID - 19 PANDEMIC RESPONSE 1 FORWARD - LOOKING STATEMENT This presentation contains forward - looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements are based on the current beliefs and expectations of CBU’s management and are subject to significant risks and uncertainties. Actual results may differ from those set f

CBU / Community Bank System, Inc. 425 - Merger Prospectus - 425

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 20, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificati

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System Reports First Quarter 2020 Results and COVID-19 Pandemic Response SYRACUSE, N.Y. — April 20, 2020 — Community Bank System, Inc. (NYSE: CBU) reported first quarter 2020 net income of $40.1 million

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 20, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificati

APRIL 2020 COVID - 19 PANDEMIC RESPONSE

Exhibit 99.2 APRIL 2020 COVID - 19 PANDEMIC RESPONSE 1 FORWARD - LOOKING STATEMENT This presentation contains forward - looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements are based on the current beliefs and expectations of CBU’s management and are subject to significant risks and uncertainties. Actual results may differ from those set f

CBU / Community Bank System, Inc. DEF 14A - - DEF 14A

DEF 14A 1 tm2012019-2def14a.htm DEF 14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Ru

CBU / Community Bank System, Inc. DEFA14A - - DEFA14A

DEFA14A 1 tv517623defa14a.htm DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commissi

CBU / Community Bank System, Inc. 425 - Merger Prospectus - 425

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 13, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificati

Retirement and Release Agreement, dated March 13, 2020, by and among Community Bank System, Inc., Community Bank, N.A. and Scott A. Kingsley. Incorporated by reference to Exhibit No. 10.1 to the Current Report on Form 8-K filed on March 19, 2020 (Registration No. 001-13695). (2)

Exhibit 10.1 EXECUTION VERSION RETIREMENT AND RELEASE AGREEMENT THIS RETIREMENT AND RELEASE AGREEMENT (this “Release”) is made by and among SCOTT A. KINGSLEY (“Employee”), COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered bank holding company (“CBSI”), and COMMUNITY BANK, N.A., a national banking association (“CBNA,” and together with CBSI, the “Company”), dated as of March 13, 20

10.2 Amendment to Employment Agreement, dated March 13, 2020, by and among Community Bank System, Inc., Community Bank, N.A. and Joseph F. Serbun

Exhibit 10.2 AMENDMENT TO EMPLOYMENT AGREEMENT This sets forth the terms of an Amendment to the Employment Agreement made as of January 1, 2019 between (i) COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered bank holding company (“CBSI”), and COMMUNITY BANK, N.A., a national banking association (“CBNA”), both having offices located in Dewitt, New York (collectively, the “Employer”),

10.2 Amendment to Employment Agreement, dated March 13, 2020, by and among Community Bank System, Inc., Community Bank, N.A. and Joseph F. Serbun.

Exhibit 10.2 AMENDMENT TO EMPLOYMENT AGREEMENT This sets forth the terms of an Amendment to the Employment Agreement made as of January 1, 2019 between (i) COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered bank holding company (“CBSI”), and COMMUNITY BANK, N.A., a national banking association (“CBNA”), both having offices located in Dewitt, New York (collectively, the “Employer”),

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Announces Retirement of Chief Operating Officer Scott Kingsley and Appointment of Joseph Serbun as Chief Banking Officer SYRACUSE, N.Y. — March 16, 2020 — Community Bank System, Inc. (NYSE:

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Announces Retirement of Chief Operating Officer Scott Kingsley and Appointment of Joseph Serbun as Chief Banking Officer SYRACUSE, N.Y. — March 16, 2020 — Community Bank System, Inc. (NYSE:

10.1 Retirement and Release Agreement, dated March 13, 2020, by and among Community Bank System, Inc., Community Bank, N.A. and Scott A. Kingsley.

Exhibit 10.1 EXECUTION VERSION RETIREMENT AND RELEASE AGREEMENT THIS RETIREMENT AND RELEASE AGREEMENT (this “Release”) is made by and among SCOTT A. KINGSLEY (“Employee”), COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered bank holding company (“CBSI”), and COMMUNITY BANK, N.A., a national banking association (“CBNA,” and together with CBSI, the “Company”), dated as of March 13, 20

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 13, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificati

CBU / Community Bank System, Inc. PRE 14A - - PRE 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Proxy State

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 3, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificatio

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Announces Shareholder Approval Received by Steuben Trust Corporation for Merger SYRACUSE, N.Y. — March 4, 2020 — Community Bank System, Inc. (NYSE: CBU) (the “Company”) announced that the S

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99.1 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.Y. 13214 Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396 Community Bank System, Inc. Announces Shareholder Approval Received by Steuben Trust Corporation for Merger SYRACUSE, N.Y. — March 4, 2020 — Community Bank System, Inc. (NYSE: CBU) (the “Company”) announced that the S

CBU / Community Bank System, Inc. 425 - Merger Prospectus - 425

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 3, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identificatio

Subsidiaries of Registrant As of December 31, 2019

Exhibit 21.1 Subsidiaries of Registrant As of December 31, 2019 Name Jurisdiction of Incorporation Benefit Plans Administrative Services, Inc. New York Benefit Plans Administrative Services, LLC New York BPAS Actuarial and Pension Services, LLC New York BPAS Trust Company of Puerto Rico Puerto Rico Brilie Corporation New York CBNA Preferred Funding Corp. Delaware CBNA Treasury Management Corporati

DESCRIPTION OF COMMUNITY BANK SYSTEM, INC.’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934

Exhibit 4.5 DESCRIPTION OF COMMUNITY BANK SYSTEM, INC.’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 As of December 31, 2019, Community Bank System, Inc. (the “Company” or “our”) had one class of securities, our common stock, par value $1.00 per share (“Common Stock”), registered under Section 12 of the Securities Exchange Act of 1934, as amended. The Common

Annual Report - 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2019 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-13695 (Exact name of registrant a

CBU / Community Bank System, Inc. / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 11)* Name of issuer: Community Bank System Inc Title of Class of Securities: Common Stock CUSIP Number: 203607106 Date of Event Which Requires Filing of this Statement: December 31, 2019 Check the appropriate box to designate the rule pursuant to which this Schedule is f

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.

Joseph E. Sutaris, EVP & Chief Financial Officer Office: (315) 445-7396

Exhibit 99 News Release For further information, please contact: 5790 Widewaters Parkway, DeWitt, N.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 22, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identifica

CBU / Community Bank System, Inc. 425 - Merger Prospectus - 425

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 22, 2020 (Exact name of registrant as specified in its charter) Delaware 001-13695 16-1213679 (State or other jurisdiction of (Commission File Number) (IRS Employer Identifica

PROPOSED MERGER — YOUR VOTE IS VERY IMPORTANT

TABLE OF CONTENTS  Filed Pursuant to Rule 424(b)(3)  Registration No. 333-235696 PROPOSED MERGER — YOUR VOTE IS VERY IMPORTANT Dear Shareholder: On October 18, 2019, Steuben Trust Corporation (“Steuben”) entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Community Bank System, Inc. (“Community Bank System”) providing for the acquisition of Steuben by Community Bank System.

CBU / Community Bank System, Inc. S-4/A - - FORM S-4/A

TABLE OF CONTENTS As filed with the Securities and Exchange Commission on January 8, 2020 Registration No.

Form of proxy card for the special meeting of the shareholders of Steuben Trust Corporation

Exhibit 99.1 SPECIAL MEETING OF SHAREHOLDERS OF STEUBEN TRUST CORPORATION March 3, 2020 3:00 p.m., Eastern Time NOTICE OF INTERNET AVAILABILITY OF PROXY MATERIALS: The Notice of Meeting, Proxy Statement and Proxy Card information are available at http://www.astproxyportal.com/ast/08642 Please sign, date and mail your proxy card in the envelope provided as soon as possible. Signature of Shareholder

CBU / Community Bank System, Inc. CORRESP - -

January 8, 2020 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance 100 F Street N.

Employment Agreement, dated December 31, 2019, by and among Community Bank System, Inc., Community Bank, N.A. and George J. Getman. Incorporated by reference to Exhibit No. 10.2 to the Current Report on Form 8-K filed on January 7, 2020 (Registration No. 001-13695). (1)

Exhibit 10.2 EMPLOYMENT AGREEMENT This sets forth the terms of the Employment Agreement executed on December 31, 2019 between (i) COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered bank holding company (“CBSI”), and COMMUNITY BANK, N.A., a national banking association (“CBNA”), both having offices in DeWitt, New York (collectively, the “Employer”), and (ii) GEORGE J. GETMAN, an ind

Employment Agreement, dated December 31, 2019, by and among Community Bank System, Inc., Community Bank, N.A. and Scott A. Kingsley. Incorporated by reference to Exhibit No. 10.1 to the Current Report on Form 8-K filed on January 7, 2020 (Registration No. 001-13695). (2)

Exhibit 10.1 EMPLOYMENT AGREEMENT This sets forth the terms of the Employment Agreement executed on December 31, 2019 between (i) COMMUNITY BANK SYSTEM, INC., a Delaware corporation and registered bank holding company (“CBSI”), and COMMUNITY BANK, N.A., a national banking association (“CBNA”), both having offices located in Dewitt, New York (collectively, the "Employer"), and (ii) SCOTT A. KINGSLE