10 U.S.C. § 12002

(a) The authorized strengths of the National Guard and the reserve components of the Army and the Air Force, exclusive of members who are included in the strengths authorized for members of the Army and Air Force, respectively, on active duty, are as follows: Army National Guard and the Army National Guard of the United States 600,000 Army Reserve 980,000 Air National Guard and the Air National Guard of the United States 150,000 Air Force Reserve 500,000. (b) The strength authorized by this section for the Army National Guard and the Army National Guard of the United States, and the strength authorized by this section for the Air National Guard and the Air National Guard of the United States, shall be allocated among the States.