X0306 4 2022-12-06 0 0000926282 ADTRAN Holdings, Inc. ADTN 0001929900 Hey Johanna C/O ADTRAN HOLDINGS, INC. 901 EXPLORER BOULEVARD HUNTSVILLE AL 35806-2807 1 0 0 0 Common Stock 1908 D Dividend Equivalent Rights 2022-12-06 4 A 0 8.861 19.38 A Common Stock 8.861 16.426 D On our previous filing on September 6, 2022, the dividend equivalent rights were inadvertently reported in Table I as non-derivative securities acquired. This report properly reflects the dividend equivalent rights as acquired derivative securities in Table II. Represents quarterly cash dividends paid on restricted stock awards (RSAs), which are credited to a bookkeeping account and hypothetically invested in shares of common stock until the underlying RSAs vest. Upon vesting, the Company pays the Reporting Person the accumulated value of the bookkeeping account in the form of whole shares of common stock, plus any remaining cash. /s/ Michael Foliano, by power of attorney 2022-09-08