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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1. Name and Address of Reporting Person * Glingener Christoph 2. Issuer Name and Ticker or Trading Symbol ADTRAN Holdings, Inc. [ADTN] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Chief Technology Officer (Last) (First) (Middle) C/O ADTRAN HOLDINGS, INC., 901 EXPLORER BOULEVARD 3. Date of Earliest Transaction (Month/Day/Year) 05/07/2026 (Street) HUNTSVILLE, AL 35806-2807 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 05/07/2026 M(1) 41,220 A $7.01 87,865 D Common Stock 05/07/2026 S(1) 41,220 D $14.73(2) 46,645 D Common Stock 05/07/2026 M(1) 84,895 A $12.17 131,540 D Common Stock 05/07/2026 S(1) 84,895 D $15.06(3) 46,645 D Common Stock 05/08/2026 M(1) 22,277 A $12.17 68,922 D Common Stock 05/08/2026 S(1) 22,277 D $15(4) 46,645 D

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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

Stock Option

$7.01

05/07/2026

M(1)

41,220

(5)

05/14/2027

Common Stock

41,220

$ 0

0

D

Stock Options

$12.17

05/07/2026

M(1)

84,895

(5)

05/14/2028

Common Stock

84,895

$ 0

22,277

D

Stock Option

$12.17

05/08/2026

M(1)

22,277

(5)

05/14/2028

Common Stock

22,277

$ 0

0

D

Stock Option

$19.08

(6)

05/14/2029

Common Stock

85,383

85,383

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Glingener Christoph C/O ADTRAN HOLDINGS, INC. 901 EXPLORER BOULEVARD HUNTSVILLE, AL 35806-2807			Chief Technology Officer

Signatures

/s/ Dan Ragsdale, by power of attorney		05/11/2026
**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)	The transactions reported on this Form 4 were effectuated pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 12, 2025.
(2)	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $14.355 to $15.69, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within this range.
(3)	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.00 to $15.69, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within this range.
(4)	These shares were sold in a single transaction at $15.00 per share.
(5)	The stock option vested and was fully exercisable.
(6)	The stock option vests on May 15, 2026, which is the fourth anniversary of the date of the grant.

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