Upon commissioning, the destroyer reported for duty with Destroyer Division 13 (DesDiv 13), Destroyer Squadron 2 (DesRon 2), Atlantic Fleet. She performed her first significant service for the Navy at Trepassey Bay in May 1919 when she served as one of the pickets for the transatlantic flight attempt by three Curtiss NC flying boats. One of the boats—"NC-4"—completed the flight successfully. "Aaron Ward" continued to serve with Atlantic Fleet until September, at which time she was transferred to the Pacific. Her first assignment there consisted of a month of salvage operations in Angeles Bay, Baja California, Mexico, to recover a downed Army DH.4B observation plane and the bodies of its crew who had been murdered by Mexican fishermen. At the conclusion of that mission, she began training operations with the Battle Fleet. On 17 July 1920, the Navy adopted the alphanumeric system of hull designations, and Aaron Ward became DD-132 (before this, she had been Destroyer No. 132). Her work with Battle Fleet was interrupted early in 1921 by two rescue missions near the Panama Canal Zone. Between January and March of that year, she cruised the waters along the coast of the Canal Zone searching for the flying boat "NC-6", which had crashed in the vicinity. In February, she turned from that mission to pursue another errand of mercy, the rescue of survivors from the destroyer which had sunk after a collision with the merchant vessel on 26 February. "Aaron Ward" resumed normal duty with the Battle Fleet in March 1921, and continued that duty until she was decommissioned on 17 June 1922 and berthed with the Reserve Fleet at San Diego.