Operations during the campaign continued into January 1944, with the invasion of Kwajalein; by this time, "Massachusetts" had been transferred to TG 58.1, under the command of Fifth Fleet. For much of the Pacific War, "Massachusetts" served with the fast carrier task force, at that time designated TF 58, screening the carriers from surface attacks and contributing her heavy anti-aircraft battery against Japanese air attacks. The carriers struck numerous targets in the Marshalls, again to isolate the garrison on Kwajalein. "Massachusetts" bombarded the island on 30 January in company with "Washington", "North Carolina", and "Indiana", the day before marines went ashore.