10 U.S.C. § 155

(a) Appointment of Officers to Joint Staff .— (1) There is a Joint Staff under the Chairman of the Joint Chiefs of Staff. The Joint Staff assists the Chairman and, subject to the authority, direction, and control of the Chairman, the other members of the Joint Chiefs of Staff in carrying out their responsibilities. (2) Officers of the armed forces (other than the Coast Guard) assigned to serve on the Joint Staff shall be selected by the Chairman in approximately equal numbers from— (A) the Army; (B) the Navy and the Marine Corps; and (C) the Air Force and the Space Force. (3) Selection of officers of an armed force to serve on the Joint Staff shall be made by the Chairman from a list of officers submitted by the Secretary of the military department having jurisdiction over that armed force. Each officer whose name is submitted shall be among those officers considered to be the most outstanding officers of that armed force. The Chairman may specify the number of officers to be included on any such list. (b) Director .— The Chairman of the Joint Chiefs of Staff, after consultation with the other members of the Joint Chiefs of Staff and with the approval of the Secretary of Defense, may select an officer to serve as Director of the Joint Staff. (c) Management of Joint Staff .— The Chairman of the Joint Chiefs of Staff manages the Joint Staff and the Director of the Joint Staff. The Joint Staff shall perform such duties as the Chairman prescribes and shall perform such duties under such procedures as the Chairman prescribes. (d) Operation of Joint Staff .— The Secretary of Defense shall ensure that the Joint Staff is independently organized and operated so that the Joint Staff supports the Chairman of the Joint Chiefs of Staff in meeting the congressional purpose set forth in the last clause of section 2 of the National Security Act of 1947 ( 50 U.S.C. 3002 ) to provide— (1) for the unified strategic direction of the combatant forces; (2) for their operation under unified command; and (3) for their integration into an efficient team of land, naval, and air forces. (e) Prohibition of Function as Armed Forces General Staff .— The Joint Staff shall not operate or be organized as an overall Armed Forces General Staff and shall have no executive authority. The Joint Staff may be organized and may operate along conventional staff lines. (f) Tour of Duty of Joint Staff Officers .— (1) An officer who is assigned or detailed to permanent duty on the Joint Staff may not serve for a tour of duty of more than four years. However, such a tour of duty may be extended with the approval of the Secretary of Defense. (2) In accordance with procedures established by the Secretary of Defense, the Chairman of the Joint Chiefs of Staff may suspend from duty and recommend the reassignment of any officer assigned to the Joint Staff. Upon receipt of such a recommendation, the Secretary concerned shall promptly reassign the officer. (3) An officer completing a tour of duty with the Joint Staff may not be assigned or detailed to permanent duty on the Joint Staff within two years after relief from that duty except with the approval of the Secretary. (4) Paragraphs (1) and (3) do not apply— (A) in time of war; or (B) during a national emergency declared by the President or Congress. (g) Composition of Joint Staff .— (1) The Joint Staff is composed of all members of the armed forces and civilian employees assigned or detailed to permanent duty in the executive part of the Department of Defense to perform the functions and duties prescribed under subsections (a) and (c). (2) The Joint Staff does not include members of the armed forces or civilian employees assigned or detailed to permanent duty in a military department. (h) Personnel Limitations .— (1) The total number of members of the armed forces and civilian employees assigned or detailed to permanent duty for the Joint Staff may not exceed 2,250. (2) Not more than 1,500 members of the armed forces on the active-duty list may be assigned or detailed to permanent duty for the Joint Staff. (3) The limitations in paragraphs (1) and (2) do not apply in time of war. (4) Each limitation in paragraphs (1) and (2) may be exceeded by a number equal to 15 percent of such limitation in time of national emergency.