Each US Army armored division was allocated an anti-aircraft artillery (AAA) battalion of four companies, each equipped with eight M15 CGMCs and eight M45 Quadmount-equipped M16 MGMCs. At corps and army level, each AAA battalion was equipped with thirty-two of each vehicle. After first seeing action in the Allied invasion of Italy, the M15 and M15A1 served through the rest of the Italian Campaign, the Allied invasion of Normandy, Operation Dragoon in southern France, and throughout the fighting on the Western Front. They were often used in ground support roles, as Allied air superiority left few German aircraft to engage. The vehicles were also used in the Pacific Theater during the campaign to liberate the Philippines and during the Battle of Okinawa. The M15 "Special" was used by the 209th AAA Battalion in the Philippines from 1944 to 1945.