Provide general and direct support and sustained combat service support above the organic capabilities of the support element of the Marine Air-Ground Task Force (MAGTF). These supported units maybe in garrison, combat, and/or in separate locations. The MLG will Support the MAGTF in amphibious assaults and subsequent operations ashore
On 6 February 1966, the Headquarters of the 4th Force Service Support Regiment was activated at the Armed Forces Reserve Center in Midland, Texas. During January 1968, the headquarters relocated to the Marine Reserve Training Center, Orlando, Florida. The headquarters again relocated to the Navy and Marine Corps Reserve Training Center, Atlanta, Georgia during 1971. In May 1976, the unit was redesignated the 4th Force Service Support Group, Fleet Marine Force. In January, 1987, the headquarters relocated to Marietta, Georgia. The flag of the 4th FSSG was moved to its present site in New Orleans in February 1992.