| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| Karaivanov Dimitar | President & CEO, Director | C/O COMMUNITY FINANCIAL SYSTEM, INC., 333 BUTTERNUT DRIVE, SYRACUSE | /s/ Danielle M. Cima, pursuant to a Confirming Statement executed by Dimitar Karaivanov | 04 Mar 2026 | 0001866135 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | CBU | Common Stock | Tax liability | -2,501 | -11% | $60.55* | 21,258 | 02 Mar 2026 | Direct | F1 | |
| holding | CBU | Common Stock | 3,271 | 02 Mar 2026 | By 401(k) Plan | F2 |
| Id | Content |
|---|---|
| F1 | Payment of tax liability associated with vesting of restricted stock award. |
| F2 | The number of shares reported herein acquired pursuant to Community Financial System, Inc.'s 401(k) Plan and are based on a current plan statement. |