"Porterfield" 's was tasked to screen escort carriers during the Marianas invasion. The group sortied from Pearl Harbor 30 June, with "Porterfield"s group of carriers supplying air cover for the advance. The group arrived off Saipan 15 June and enemy air attacks began shortly after. "Porterfield" stayed with the force, rescuing two pilots, before being sent to Eniwetok 1 July for dry-docking. After her repairs, the ship reached Saipan again on 11 July and operated with the carrier screen until sent to Guam early in August.