Business Description

Corporation Law. Its principal office is located at 333 Butternut Drive, Syracuse, New York 13214. The Company’s business philosophy is to operate as a diversified financial services enterprise providing a broad array of banking and other financial services to retail, commercial, institutional and governmental customers. The Company is a registered financial holding company which wholly-owns two significant subsidiaries: Community Bank, N.A. (the “Bank” or “CBNA”), and Benefit Plans Administrative Services, Inc. (“BPAS”). As of December 31, 2025, BPAS owns five subsidiaries: Benefit Plans Administrative Services, LLC (“BPA”), a provider of defined contribution plan administration services; Northeast Retirement Services, LLC (“NRS”), a provider of institutional transfer agency, master recordkeeping services, fund administration, trust, and retirement plan services; BPAS Actuarial & Pension Services, LLC (“BPAS-APS”), a provider of actuarial and benefit consulting services; BPAS Trust Company of Puerto Rico, a provider of trust and benefit plan administration services; and Hand Benefits & Trust Company (“HB&T”), a provider of collective investment fund administration and institutional trust services. NRS owns one subsidiary, Global Trust Company, Inc. (“GTC”), a non-depository trust company which provides fiduciary services for collective investment trusts and other products. HB&T owns one subsidiary, Hand Securities, Inc. (“HSI”), an introducing broker-dealer. ​ As of December 31, 2025, the Bank operates 192 full-service branches and 8 drive-thru only locations throughout 42 counties of Upstate New York, 9 counties of Northeastern Pennsylvania, 12 counties of Vermont, 1 county of Western Massachusetts and 1 county of Southern New Hampshire, offering a range of commercial and retail banking services. The Bank owns the following operating subsidiaries: CBNA Preferred Funding Corporation (“PFC”), CBNA Treasury Management Corporation (“TMC”), Nottingham Investment Services, Inc. (“NISI”), Nottingham Advisors, Inc. (“Nottingham Advisors”), OneGroup NY, Inc. (“OneGroup”), Nottingham Wealth Partners, Inc. (“Wealth Partners”) and Oneida Preferred Funding II LLC (“OPFC II”). OneGroup is a full-service insurance agency offering personal and commercial lines of insurance and other risk management products and services. PFC and OPFC II primarily act as investors in residential and commercial real estate activities. TMC provides cash management, investment, and treasury services to the Bank. NISI and Wealth Partners provide broker-dealer and investment advisory services. Nottingham Advisors provides asset management services to individuals, corporations, corporate pension and profit sharing plans, and foundations. ​ The Company maintains a website at https://communityfinancialsystem.com. Annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and amendments to those reports, are available on the Company’s website free of charge as soon as reasonably practicable after such reports or amendments are electronically filed with or furnished to the Securities and Exchange Commission (“SEC”). The information posted on the website is not incorporated into or a part of this filing. Copies of all documents filed with the SEC can also be obtained by visiting the SEC’s Public Reference Room at 100 F Street, NE, Washington, DC 20549, by calling the SEC at 1-800-SEC-0330 or by accessing the SEC’s website at https://www.sec.gov. ​ Current Year Acquisitions ​ 7 Branches from Santander Bank, N.A. in the Lehigh Valley Market ​ On November 7, 2025, the Company, through its subsidiary CBNA, completed the acquisition of seven branch locations in the Allentown, Pennsylvania area from Santander Bank, N.A. (“Santander”), including certain branch-related loans and deposits, acquiring $31.9 million of loans and $543.7 million of deposits. Total cash consideration was $80.9 million, including a deposit premium of 8%, or $43.5 million, and the Company recorded core deposit intangibles of $11.9 million and goodwill of $32.0 million. ​ ​ 3 Table of Contents Financial Services Companies ​ During 2025, the Company, through its subsidiaries OneGroup, BPA, BPAS-APS and NISI, completed the acquisitions of certain assets of financial services companies. The assets were acquired from companies that provide insurance, employee benefit and wealth management services.…