Following shakedown out of San Diego, Geneva departed that port 19 May 1945 with over 500 marines and sailors for Pearl Harbor and Majuro atoll, Marshall Islands, where she arrived 7 June.

She returned to Okinawa 15 September, weathered a typhoon, and embarked the 11th Artillery Regiment of the 4th Marine Battalion and their cargo for passage to Taku, China, where she arrived 5 October.

Geneva departed Qingdao on 23 November, embarked over a thousand homeward-bound veterans at Luzon, Philippines, and reached San Francisco 19 December.

The attack transport returned to Pearl Harbor 2 March for training in the Hawaiian area until she departed 17 May to serve in Operation Crossroads, a joint atomic bomb experiment of the Army and Navy in the Marshall Islands at Bikini Atoll.

Her crew then transferred to USS Appling (APA-58) since Geneva was to be one of the target ships in "Test Able" on the morning of 1 July 1946 when the fourth atomic bomb to be exploded and the first ever detonated over water was to be dropped from a B-29.

Geneva was in normal operation 4 days after that explosion, steaming to Kwajalein 25 August, then proceeding via Hawaii to San Francisco, where she arrived 5 November.

She was returned to the United States Maritime Commission on 2 April and joined the National Defense Reserve Fleet at James River, Virginia.