10 U.S. Code Chapter 5 - Joint Chiefs of Staff
"(a) Composition.—There are in the Department of Defense the Joint Chiefs of Staff, headed by the Chairman of the Joint Chiefs of Staff. The Joint Chiefs of Staff consist of the following: (1) The Chairman. (2) The Vice Chairman. (3) The Chief of Staff of the Army. (4) The Chief of Naval Operations. (5) The Chief of Staff of the Air Force. (6) The Commandant of the Marine Corps. (7) The Chief of the National Guard Bureau. (8) The Chief of Space Operations."