Following her successful operations off North Africa, "Massachusetts" was taken in for an overhaul in the Boston Navy Yard. After the refitting, the ship sailed for the Pacific theater, and arrived in Nouméa on 4 March. The battleship supported operations in the South Pacific over the next months, including guarding convoy lanes, escorting aircraft carriers, and bombarding Japanese positions on various islands, including Nauru (8 December 1943) and Kwajalein (30 January 1944). Returning to carrier protection after the latter bombardment, "Massachusetts" provided anti-aircraft defense while Allied air attacks were sent against Saipan, Tinian and Guam; she also supported later invasions of the Caroline Islands and Hollandia. After bombarding Ponape Island on 1 May, the ship set course for the Puget Sound Navy Yard for an overhaul and to have her gun barrels relined, as they had worn out.