Originally classified as a patrol gunboat, PG-146, Coronado was reclassified as a patrol frigate on 15 April 1943. She was laid down by the Consolidated Steel Corporation of Wilmington, California, under a Maritime Commission contract (MC Type T. S2-S2-AQ1) on 6 May 1943. She was launched on 17 June 1943, sponsored by Mrs. J. R. Crutchfield, and commissioned on 17 November 1943 with United States Coast Guard Lieutenant Commander Ned Weckesser Sprow in command.