Sergeant Major is the highest enlisted rank in the Army, and the base rank required for the leadership position of Command Sergeant Major. A Sergeant Major assists Officers in a battalion-sized force of 300 to 1,000 soldiers, and leads soldiers and junior officers placed directly under his command. A Sergeant Major may also serve as the senior non-commissioned officer at a battallion-sized headquarters unit.  Command Sergeant Major is the 12th rank in the United States Army , ranking above Sergeant Major and directly below Sergeant Major of the Army.