At the outbreak of the World War II in September 1939, Coffman was appointed quartermaster of the Depot of Supplies at Naval Station Norfolk. He subsequently spent some time as quartermaster of the Marine Barracks Quantico and later also at Camp Lejeune, before he was appointed Supply officer of 1st Marine Division at Quantico under Major General Philip H. Torrey in January 1942. The 1st Division went overseas during the summer 1942 and subsequently participated with the part of the division in the Landing at Tulagi.