Members of the Army National Guard of the United States and the Air National Guard of the United States are not in active Federal service except when ordered thereto under law.
Structure US Code
Subtitle E— Reserve Components
CHAPTER 1211— NATIONAL GUARD MEMBERS IN FEDERAL SERVICE
§ 12401. Army and Air National Guard of the United States: status
§ 12404. Army and Air National Guard of the United States: mobilization; maintenance of organization
§ 12405. National Guard in Federal service: status
§ 12406. National Guard in Federal service: call
§ 12407. National Guard in Federal service: period of service; apportionment
§ 12408. National Guard in Federal service: physical examination