Sec Form 4 Filing - Gardella David A @ Donnelley Financial Solutions, Inc. - 2025-03-03

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Gardella David A 2. Issuer Name and Ticker or Trading Symbol Donnelley Financial Solutions, Inc. [ DFIN] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Chief Financial Officer (Last) (First) (Middle) C/O DONNELLEY FINANCIAL SOLUTIONS, 391 STEEL WAY 3. Date of Earliest Transaction (MM/DD/YY) 03/03/2025 (Street) LANCASTER, PA17601 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 03/03/2025 F( 1 ) 4,553 D $ 47.54 192,853 D Common Stock 03/03/2025 A( 2 ) 21,363 A $ 47.54 214,216 D Common Stock 03/03/2025 F( 3 ) 16,381 D $ 47.54 197,835 D Common Stock 03/03/2025 A 9,148 A 206,983 D Common Stock 03/03/2025 A 16,440 A 223,423 D Common Stock 03/04/2025 F( 1 ) 1,840 D $ 46.1 221,583 ( 6 ) D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Gardella David A C/O DONNELLEY FINANCIAL SOLUTIONS 391 STEEL WAY LANCASTER, PA17601 Chief Financial Officer Signatures William Zola, pursuant to power of attorney 03/05/2025 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Shares were withheld as payment of a tax liability incident to vesting of restricted stock units issued in accordance with Rule 16b-3. ( 2 )Represents earned portions of Company granted PSUs issued in 2022 pursuant to a Rule 16b-3 plan for which performance has been determined. On March 3, 2025, the Compensation Committee determined the achievement of the performance goals for 2024 and 2022-2024, resulting in 11,403 and 9,960 earned stock units, respectively. The Compensation Committee had previously determined the achievement of the performance goals for 2022 and 2023, resulting in 10,330 and 5,284 earned stock units. The total earned stock units of 36,977 were delivered on March 3, 2025. ( 3 )Shares were withheld as payment of a tax liability incident to vesting of performance stock units issued in accordance with Rule 16b-3. ( 4 )Represents earned portions of the Company granted PSUs issued in 2023 and 2024 pursuant to a Rule 16b-3 plan for which performance has been determined. For the 2023 PSUs, 25% is subject to performance goals related to 2024 performance, which was determined by the Compensation Committee to be achieved on March 3, 2025 and resulted in 7,469 earned stock units. For the 2024 PSUs, 10% is subject to performance goals related to 2024 performance, which was determined by the Compensation Committee to be achieved on March 3, 2025 and resulted in 1,679 earned stock units, subject to additional modification based on the Company's relative total shareholder return at the end of 2026. Earned stock units for the 2023 and 2024 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 2025 and 2026 respectively, and final performance and payout is determined. ( 5 )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, 2026. ( 6 )Includes 171,367 shares held directly, 29,948 restricted stock unit, and 20,268 earned performance share units with additional service-based vesting.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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