Transaction Details

Footnotes

Includes 78.04 shares acquired on January 12, 2026 pursuant to the Community Financial System, Inc. Dividend Reinvestment Plan. | Includes 86.2 shares acquired on January 12, 2026 pursuant to the Community Financial System, Inc. Dividend Reinvestment Plan. | The reporting person disclaims beneficial ownership of these securities, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or any other purpose. | The units of phantom stock were acquired through Merchants Bancshares, Inc.'s ("Merchants") deferred compensation plan. Each unit of phantom stock is the economic equivalent of one share of Community Financial System, Inc. common stock. The units of phantom stock relating to such deferred compensation plan will be settled in Community Financial System, Inc. common stock at future dates selected by the reporting person. | Includes 77.299 units of phantom stock acquired on January 12, 2026 under the Merchants' deferred compensation plan's dividend reinvestment feature | Each unit of phantom stock is the economic equivalent of one share of Community Financial System, Inc. common stock. The units of phantom stock relating to the Deferred Compensation Plan for Directors (the "DCP for Directors"), will be settled in Community Financial System, Inc. common stock at future dates selected by the reporting person. | Includes 67.3778 units of phantom stock acquired as dividend equivalents on January 12, 2026 under the DCP for Directors. | The reporting person has received deferred stock units under the Community Financial System, Inc. 2022 Long-Term Incentive Plan, as amended (the "LTIP"). Each phantom stock unit which represents a deferred stock unit is the economic equivalent of one share of Community Financial System, Inc. common stock and will be settled in common stock at a predetermined date. | Includes 55.1073 units of phantom stock acquired on January 12, 2026 under the LTIP's dividend reinvestment feature.