"Dortch" served in the screen of the Fast Carrier Task Force TF 58 during the capture and occupation of the Marshall Islands from 29 January 1944. She took part in the initial raids on Truk of 16 February and 17 and on the Marianas on 23 February, then sailed with the task group providing air cover for landings on Emirau Island in March. Later that month she rejoined TF 58 for raids on Palau, Yap, Ulithi and Woleai from 30 March to 1 April; support of the Hollandia operation in New Guinea on 21 April and 22; and a repeat raid on Truk from 29 April to 1 May.