X0306 4 2015-12-31 0 0000926282 ADTRAN INC ADTN 0000937725 NICHOLS ROY J 901 EXPLORER BLVD. HUNTSVILLE AL 35806 1 0 0 0 Common Stock 2015-12-31 4 M 0 76.164 A 29079.164 D Common Stock 2015-12-31 4 D 0 0.164 17.22 D 29079 D Common Stock 2015-12-31 4 A 0 4646 0.00 A 33725 D Common Stock 23328 I by Trust Common Stock 5421 I by Spouse Common Stock 6 I by Spouse as UTMA custodian for granddaughter Common Stock 6 I by Spouse as UTMA custodian for grandson Dividend Equivalent Rights 2015-12-31 4 M 0 76.164 0.00 D Common Stock 76.164 0 D Settlement of dividend equivalent rights in connection with lapse of restriction on restricted stock. The rights accrued when and as dividends were paid on the Company's common stock and are paid in whole shares of common stock with the remainder paid in cash. Each dividend equivalent right is the economic equivalent of one share of the Company's common stock. Represents a grant of restricted stock that vests at 100% on the 1st anniversary of the grant. Gayle S. Ellis by Power of Attorney 2016-01-04