He advises the Commandant of the Marine Corps on matters pertaining to enlisted Marines and accompanies the Commandant on all major command visits and other official trips.   The Sergeant Major also serves on the Enlisted Performance Board, and the Uniform Board.

The Sergeant Major of the Marine Corps is selected by the Commandant from nominees submitted by a board of Marine Generals.   The duration of his appointment is determined by the Commandant.

The Marine Corps was the first service to adopt the billet of Sergeant Major. Counterpart in other military services includes the Sergeant Major of the Army, Master Chief Petty Officer of the Navy, and Chief Master Sergeant of the Air Force.