X0306 4/A 2022-09-01 2022-09-06 0 0000926282 ADTRAN Holdings, Inc. ADTN 0001371377 Wilson James Denson Jr C/O ADTRAN HOLDINGS, INC. 901 EXPLORER BLVD. HUNTSVILLE AL 35806 0 1 0 0 Chief Revenue Officer Common Stock 2022-09-04 4 P 0 102.333 22.90 A 128560.486 D Common Stock 4133.064 I 401(k) Plan Phantom Stock 2022-09-01 4 P 0 67.263 23.01 A Common Stock 67.263 17263.736 D Stock Option 23.64 2023-11-02 Common Stock 20034 20034 D Reflects shares acquired through the automatic reinvestment of dividends paid on the Issuer's common stock. Includes 15.653 shares acquired since the reporting person's prior Form 4 from the automatic reinvestment of dividends. Represents shares of phantom stock of the Issuer that have been acquired through the automatic reinvestment of dividends paid on the Issuer's common stock held in the reporting person's account under the Issuer's deferred compensation plan. The phantom shares become payable in cash six months after the reporting person's separation of service with the Issuer. The options granted to the reporting person vested in four equal annual installments beginning on November 2, 2013. The reporting person realized short-swing profits under Section 16(b) of the Exchange Act as a result of shares acquired through the automatic reinvestment of dividends paid on the Issuer's common stock held in the reporting person's personal brokerage accounts on September 4, 2022 being matched against prior sales of the Issuer's common stock by the reporting person. The reporting person has paid to the Issuer the maximum amount of short-swing profits that may have been realized by the reporting person. /s/ Michael Foliano, by power of attorney 2022-09-08