32 U.S.C. § 502 — Required drills and field exercises

(a) Under regulations the Secretary of the Army or the Secretary of the Air Force sets, every National Guard company, battery, squadron, and detachment — unless the Secretary excuses it — must: (1) assemble for drill and instruction, including indoor target practice, at least 48 times a year; and (2) take part in encampments, maneuvers, outdoor target practice, or other exercises for at least 15 days a year. However, a member who has already served on active duty for a year or longer doesn't have to take part in that training if it starts during the last 120 days of the member's required Guard membership. (b) An assembly for drill and instruction can be a single formation of the unit, or — when the Secretary concerned allows it — a series of formations covering different parts of the unit. To count a series as one assembly, every part of the unit must be included within 90 consecutive days. (c) Total attendance across the series of formations counts as attendance for the entire required assembly. No member may be counted more than once, or get credit for more than one required attendance period, no matter how many formations in the series they attend. (d) A unit gets no credit for a drill or indoor-target-practice assembly unless: (1) at least the minimum number of members set by the President shows up; (2) each credited period of duty or instruction lasts at least one and a half hours; and (3) the training is the type the Secretary concerned prescribes. (e) A qualified National Guard member who flies an aircraft under proper orders may get drill-attendance credit for that flight, if the flight is what kept the member from attending a regularly scheduled drill. (f)(1) Under regulations the Secretary of the Army or Secretary of the Air Force sets, a Guard member may be ordered — without their consent but with pay and allowances — or may agree, with or without pay, to perform extra training or other duty beyond what subsection (a) requires. (2) That extra duty may include supporting operations or missions the member's unit carries out at the President's or the Secretary of Defense's request, or supporting training operations and missions the Secretary concerned assigns to the National Guard — but only if that training happens in the United States, Puerto Rico, or U.S. possessions, and only involves instructing active-duty military, foreign military (under the same rules that apply to active-duty troops), Defense Department contractor personnel, or Defense Department civilian employees. (3) Duty performed without pay still counts for all purposes as if it were duty performed with pay.