Sergeant Major Affiliation Higher rank Lower rank Command Known Sergeant Majors [Source] • [Talk] Sergeant Major is an E-9 rank of the UNSC Marine Corps and UNSC Army. It is a staff non-commissioned officer rank, and is equal in pay grade to Master Gunnery Sergeant in the Marines or Command Sergeant Major in the Army, although the two have different responsibilities. Sergeant Major is equal to the rank of Master Chief Petty Officer in the UNSC Navy. A Marine Sgt Maj is similar to a Command Chief Master Sergeant in the UNSC Air Force and Command Sergeant Major in the Army. An Army SGM is similar to a Chief Master Sergeant in the Air Force or a Master Gunnery Sergeant in the Marines.