10 U.S.C. § 10152

An inactive status list shall be maintained in the Standby Reserve. Whenever an authority designated by the Secretary concerned considers that it is in the best interest of the armed force concerned, a member in the Standby Reserve who is not required to remain a Reserve, and who cannot participate in prescribed training, may, if qualified, be transferred to the inactive status list under regulations to be prescribed by the Secretary concerned. These regulations shall fix the conditions under which such a member is entitled to be returned to an active status.