Donnelley Financial Solutions, Inc.

1. The reported price represents a weighted average sale price. The range of prices at which common stock was sold was $52.26 to $52.485 per share. The Reporting Person undertakes to provide to the staff, the issuer or a security holder full information regarding the number of shares sold at each separate price.

2. Shares were withheld as payment of a tax liability incident to vesting of restricted stock units issued in accordance with Rule 16b-3.

3. Represents earned portions of Company granted PSUs issued in 2023 pursuant to a Rule 16b-3 plan for which performance has been determined. On March 3, 2026, the Compensation Committee determined the achievement of the performance goals for 2025 and 2023-2025, resulting in 5,310 and 4,982 earned stock units, respectively. The Compensation Committee had previously determined the achievement of the performance goals for 2023 and 2024, resulting in 5,294 and 3,556 earned stock units. The total earned stock units of 19,142 were delivered on March 3, 2026.

4. Shares were withheld as payment of a tax liability incident to vesting of performance stock units issued in accordance with Rule 16b-3.

5. Represents earned portions of the Company granted PSUs issued in 2024 and 2025 pursuant to a Rule 16b-3 plan for which performance has been determined. For the 2024 PSUs, 10% is subject to performance goals related to 2025 performance, which was determined by the Compensation Committee not to be achieved on March 3, 2026 and resulted in 0 earned stock units related to that performance goal. For the 2025 PSUs, 10% is subject to goals related to 2025 performance, which was determined by the Compensation Committee to be achieved on March 3, 2026 and resulted in 1,200 earned stock units, subject to additional modification based on the Company's relative total shareholder return at the end of 2027. Earned stock units for the 2024 and 2025 PSUs remain subject to service-based vesting until each of the performance periods related to that PSU's goals is complete, at the close of 2026 and 2027 respectively, and final performance and payout is determined.

6. Company granted restricted stock units ("RSUs") issued pursuant to a Rule 16b-3 plan. The RSUs vest three equal annual installments beginning on March 3, 2027.

7. The reported price represents a weighted average sale price. The range of prices at which common stock was sold was $52.025 to $52.033 per share. The Reporting Person undertakes to provide to the staff, the issuer or a security holder full information regarding the number of shares sold at each separate price.

8. Includes 36,450 shares held directly, 22,174 restricted stock unit, and 2,179 earned performance share units with additional service-based vesting.