Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

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

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(Print or Type Responses)

1. Name and Address of Reporting Person * Oswald Stephen G 2. Issuer Name and Ticker or Trading Symbol DUCOMMUN INC /DE/ [DCO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Chairman, President & CEO (Last) (First) (Middle) 600 ANTON BLVD., SUITE 1100 3. Date of Earliest Transaction (Month/Day/Year) 03/04/2026 (Street) COSTA MESA, CA 92626 4. If Amendment, Date Original Filed (Month/Day/Year) 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 (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 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 03/04/2026 A 75,503(1) A $ 0 (2) 451,439(3) D Common Stock 03/04/2026 F 40,583(4) D $139.45 410,856 D Common Stock 03/04/2026 A 23,649(5) A $ 0 (2) 434,505 D Common Stock 03/04/2026 F 12,712(6) D $139.45 421,793 D Common Stock 03/05/2026 F 2,409(7) D $130.19 419,384 D

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

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 (Month/Day/Year)

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
Oswald Stephen G 600 ANTON BLVD. SUITE 1100 COSTA MESA, CA 92626	X		Chairman, President & CEO

Signatures

Stephen G. Oswald		03/06/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Acquired upon the settlement of performance stock units granted on May 8, 2023 under the Ducommun Incorporated Stock Incentive Plan as a result of the satisfaction of performance metrics underlying the award.
(2)	Granted as compensation for services.
(3)	The total amount of securities listed includes 279 shares of common stock acquired on January 30, 2026 through the Ducommun Incorporated Employee Stock Purchase Plan.
(4)	Represents a reduction in shares to satisfy the tax withholding obligations of the Issuer with respect to the settlement, on March 4, 2026, of 75,503 performance stock units described in footnote (1) above.
(5)	Represents the vesting of 23,649 performance restricted stock units (n/k/a revenue performance stock units) granted on May 8, 2023 as a result of the satisfaction of performance criteria underlying the award.
(6)	Represents a reduction in shares to satisfy the tax withholding obligations of the Issuer with respect to the settlement, on March 4, 2026 of 23,640 performance restricted stock units (n/k/a revenue performance stock units) as described in footnote (5) above.
(7)	Represents a reduction in shares to satisfy the tax withholding obligations of the Issuer with respect to the vesting, on March 5, 2026, of 4,480 restricted stock units.

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