32 C.F.R. § 564.38
(a) In line of duty. Medical care is authorized for members who incur a disease or injury in line of duty under the following circumstances:
(c) Armory drill status. Members who incur an injury while in an armory drill status under section 502 of title 32, U.S.C., when it is determined to be not in line of duty, may not be furnished medical care at Army expense.
(32 U.S.C. 318-320 and 502-505)