For nearly a year after leaving the yard in May 1942, "Simpson" escorted convoys up and down the United States East Coast. She made one trip to Casablanca in February 1943, and on 28 April 1943, began overhaul at the New York Navy Yard. At sea again in May, "Simpson" escorted a convoy from New York to Curaçao in the West Indies, and then made two round-trip voyages between Curaçao and Londonderry Port, Northern Ireland. On 29 August 1943, "Simpson" joined an escort carrier task group centered on and escorted a convoy from Bermuda to Casablanca. The task group then carried out antisubmarine patrols off the Azores. The group joined a westbound convoy on 22 September but resumed antisubmarine sweeps after a submarine was reported near the Azores on 26 September. "Simpson" returned to the United States on 12 October but was back in the Azores conducting additional patrols between 28 October and 9 December 1943.