What is the special E-9 rank in the Marine Corps?

The special E-9 rank in the Marine Corps is the Sergeant Major of the Marine Corps. This rank holds a unique and prestigious position within the military structure, as it serves as the senior enlisted advisor to the Commandant of the Marine Corps. The Sergeant Major of the Marine Corps is responsible for providing leadership and guidance to all enlisted Marines and ensuring their needs and concerns are addressed at the highest levels of command. This position is distinct from other E-9 ranks, such as Master Gunnery Sergeant, which focuses more on technical and operational expertise within a specific field, or Sergeant First Class and Gunnery Sergeant, which are ranks found in the Army and pertain to different branches of service. The significance and responsibilities associated with the Sergeant Major of the Marine Corps reflect its unique status as the only enlisted position of its kind within the Marine Corps hierarchy.