10 U.S.C. § 1049: Subsistence: miscellaneous persons

The following persons may be provided subsistence at the expense of the United States:(1) Enlisted members while sick in hospitals. (2) Applicants for enlistment and selective service registrants called for induction. (3) Prisoners. (4) Civilian employees, as authorized by law. (5) Supernumeraries, when necessitated by emergent military circumstances.