10 U.S.C. § 12009

(a) The authorized strength in any reserve grade, as prescribed under this chapter, for any reserve component under the jurisdiction of the Secretary of the Army or the Secretary of the Air Force is automatically increased to the minimum extent necessary to give effect to each appointment made in that grade under section 1211(a), 7036, 14304(b), 14314, or 14317 of this title. (b) An authorized strength so increased is increased for no other purpose. While an officer holds that grade, the officer whose appointment caused the increase is counted for the purpose of determining when other appointments, not under those sections, may be made in that grade.