The destroyer returned to Majuro on 6 April 1944, and a week later joined the sortie for the Hollandia landings of 21–24 April, and air raids on Truk, Satawan, and Ponape at the close of the month. Replenishment at Majuro from 4 May to 6 June preceded "Cogswell"s assignment to screen carriers during the landings in the Marianas. On 16 June, "Cogswell" was temporarily detached to join in the bombardment of Guam, rejoining her force to guard it during the momentous air Battle of the Philippine Sea on 19–20 June. She continued her screening in the raids on Palau, Ulithi, Yap, Iwo Jima, and Chichi Jima from 25 July to 5 August, during the last of which she joined in the surface gunfire which sank several ships of a Japanese convoy earlier badly mauled by carrier aircraft. From 11–30 August, she replenished at Eniwetok.