 On 29 March 1940, the 5th Medical Regiment was re-designated as the 5th Medical Battalion.The 5th Medical Battalion was assigned on 1 July 1940 to the 4th Division, the "Ivy Division" (later re-designated as the 4th Infantry Division) and activated at Fort Benning, Georgia as the 4th Medical Battalion.The unit was reorganized and re-designated on 7 July 1942 as the 4th Medical Battalion, Motorized and then again on 4 August 1943 as the 4th Medical Battalion.