Routed onward to the United States, "Tambor" arrived at San Francisco on 10 December 1944. After an extended overhaul, the submarine sailed for Puget Sound on 9 March 1945. Upon her arrival, "Tambor" began training operations with Navy patrol aircraft under Fleet Air Wing 6. On 17 September, she departed the West Coast for Portsmouth Naval Shipyard. "Tambor" was decommissioned there on 10 December 1945 and placed in reserve. In April 1947, the submarine was assigned to the Ninth Naval District to train naval reservists, and reported to the Naval Reserve Training Center, Detroit, Michigan, on 8 December. "Tambor" remained on this station until 1959, when a Board of Inspection and Survey found her unfit for further naval service. She was stricken from the Naval Vessel Register on 1 September and subsequently sold for scrap.