Columbia Financial, Inc.

1. This form reflects increases in beneficial ownership resulting from exempt acquisitions pursuant to rule 16b-3(c).

2. Stock Awards granted pursuant to the Columbia Financial, Inc. 2019 Equity Incentive plan, 25% of which vest in three approximately equal annual installments commencing on May 1, 2024; and the remaining 75% of which vest upon achievement of certain specified performance-based vesting criteria, which if achieved, such Awards would vest three years after the date of the Award.

3. Stock Awards granted pursuant to the Columbia Financial, Inc. 2019 Equity Incentive plan, 25% of which vest in three approximately equal annual installments commencing on March 6, 2025; and the remaining 75% of which vest upon achievement of certain specified performance-based vesting criteria, which if achieved, such Awards would vest three years after the date of the Award.

4. Stock Awards granted pursuant to the Columbia Financial, Inc. 2019 Equity Incentive plan, which vest upon achievement of certain specified performance-based vesting criteria, which if achieved, such Awards would vest three years after the date of the Award on March 3, 2028.

5. Stock Options granted pursuant to the Columbia Financial, Inc. 2019 Equity Incentive Plan vest in three approximately equal annual installments commencing on March 2, 2027.

6. One phantom stock unit is the economic equivalent of one share of CLBK Common Stock. Phantom stock units were granted under the Columbia Financial, Inc. 2026 Phantom Stock Plan and will be settled in cash upon distribution.

7. On the settlement date, phantom stock units will be payable in cash. The cash value will be calculated, in accordance with the Columbia Financial, Inc. 2026 Phantom Stock Plan, based on the closing stock price of the Company's Common Stock on the determination date.

8. Stock Options granted pursuant to the Columbia Financial, Inc. 2019 Equity Incentive Plan are fully vested and exercisable.

9. Stock Options granted pursuant to the Columbia Financial, Inc. 2019 Equity Incentive Plan vest in three approximately equal annual installments commencing on May 1, 2024.

10. Stock Options granted pursuant to the Columbia Financial, Inc. 2019 Equity Incentive Plan vest in three approximately equal annual installments commencing on March 6, 2025.

11. Stock Options granted pursuant to the Columbia Financial, Inc. 2019 Equity Incentive Plan vest in three approximately equal annual installments commencing on March 3, 2026.