"Stern" held her shakedown cruise off Bermuda and returned to New York for post-shakedown availability. After a short training period off Casco Bay, Maine, she escorted a convoy to Ireland and returned with another to New York. She stood out of that port, on 23 March 1944, with a convoy for North Africa and arrived at Casablanca on 2 April. On 7 May, she sailed for home with a return convoy and arrived at New York on the 17th. "Stern" made another round trip to Ireland, via Bermuda from 8 June to 2 August, and one more to Bizerte, Tunisia, which ended in New York on 7 October.