COMMUNITY FINANCIAL SYSTEM, INC.

The Company has a Code of Ethics for its Directors, officers and employees. The Code of Ethics requires that individuals avoid conflicts of interest, comply with all laws and other legal requirements, conduct business in an honest and ethical manner, and otherwise act with integrity and in the best interests of the Company. In addition, the Code of Ethics requires individuals to report illegal or unethical behavior they observe and to comply with the Foreign Corrupt Practices Act and Bribery Laws. As of March 22, 2024, the Company has not been subject to any fines for any violations of anti-corruption or anti-bribery laws.

The Company also has adopted a Code of Ethics for Senior Executive Officers that applies to its chief executive officer, chief financial officer, and other senior officers performing similar functions. This Code of Ethics for Senior Executive Officers is intended to promote honest and ethical conduct, full and accurate reporting, and compliance with laws and regulations.

The text of each Code is posted on the Company’s website at https://ir.communitybanksystem.com/corporate-overview/documents/default.aspx and is available in print free of charge to any Shareholder or interested party who requests it. The Company intends to report and post on its website any amendment to or waiver from any provision in the Code of Ethics for Senior Executive Officers as required by SEC rules.