Community Financial System, Inc. (the "Company" or "CFSI") (NYSE:CBU) will host a conference call to discuss its financial and operating results for the third quarter ended September 30, 2026.

Event:	Third Quarter 2026 Earnings Conference Call

When:	Tuesday, October 27, 2026 at 11:00 a.m. Eastern Time

Access:	Dial-In (U.S.): 1-833-630-0464
	Dial-In (International): 1-412-317-1809
	Webcast: https://app.webinar.net/EmXoj28zpxQ

Dimitar Karaivanov, President and Chief Executive Officer, and Marya Burgio Wlos, Executive Vice President and Chief Financial Officer, will discuss the Company's quarterly results. Management's prepared remarks will last approximately 15 minutes, followed by a question-and-answer session.

The Company's results for the quarter will be released prior to market open on October 27, 2026, and will also be available in the 'News' section of the Company's website at https://ir.cfsi.com/.

A replay of the webcast will be available on the site for one year at no cost.

About Community Financial System, Inc.

Community Financial System, Inc. is a diversified financial services company that is focused on four main business lines – banking services, employee benefit services, insurance services and wealth management services. Its banking subsidiary, Community Bank, N.A., is among the country’s 100 largest banking institutions with over $17 billion in assets and operates approximately 200 customer facilities across Upstate New York, Northeastern Pennsylvania, Vermont, Western Massachusetts, and Southern New Hampshire. The Company’s Benefit Plans Administrative Services, Inc. subsidiary is a leading provider of employee benefits administration, trust services, collective investment fund administration, and actuarial consulting services to customers on a national scale. The Company’s OneGroup NY, Inc. subsidiary is a top 68 U.S. insurance agency. The Company also offers comprehensive financial planning, trust administration and wealth management services through its Nottingham Financial Group operating unit. The Company is listed on the New York Stock Exchange and the Company’s stock trades under the symbol CBU. For more information about the Company and each of its four main business lines visit https://ir.cfsi.com/.

View source version on businesswire.com: https://www.businesswire.com/news/home/20260917108156/en/

For further information, please contact:

Marya Burgio Wlos, EVP & Chief Financial Officer

Office: (315) 299-2946