10 U.S.C. § 690

(a) General and Flag Officers .— Not more than 15 retired general officers of the Army, Air Force, Marine Corps, or Space Force, and not more than 15 retired flag officers of the Navy, may be on active duty at any one time. For the purposes of this subsection a retired officer ordered to active duty for a period of 60 days or less is not counted. (b) Limitation by Service .— (1) Not more than 25 officers of any one armed force may be serving on active duty concurrently pursuant to orders to active duty issued under section 688 of this title . (2) In the administration of paragraph (1), the following officers shall not be counted: (A) A chaplain who is assigned to duty as a chaplain for the period of active duty to which ordered. (B) A health care professional (as characterized by the Secretary concerned) who is assigned to duty as a health care professional for the period of the active duty to which ordered. (C) Any officer assigned to duty with the American Battle Monuments Commission for the period of active duty to which ordered. (D) Any member of the Retiree Council of the Army, Navy, or Air Force for the period on active duty to attend the annual meeting of the Retiree Council. (E) An officer who is assigned to duty as a defense attaché or service attaché for the period of active duty to which ordered. (c) Waiver for Periods of War or National Emergency .— Subsection (a) does not apply in time of war or of national emergency declared by Congress or the President after November 30, 1980 . Subsection (b) does not apply in time of war or of national emergency declared by Congress or the President.