32 U.S.C. § 325 — Relief from National Guard duty when ordered to active duty

(a) Relief Required. (1) Except as (2) allows, every Army or Air National Guard member ordered to active duty is relieved from their state, or Puerto Rico, Guam, Virgin Islands, or District of Columbia, National Guard duty, from the date the active-duty order takes effect until they are relieved from that duty. (2) An officer is not relieved from state National Guard duty under (1) while on active duty, if: (A) the President allows serving in both duty statuses at once; and (B) the Governor of the officer's state or territory, or the District of Columbia National Guard's commanding general, consents to that dual service. (b) Advance Authorization and Consent. The President and the Governor, or the District of Columbia commanding general, can give the (a)(2) authorization or consent for an officer in advance, to set up a unit's chain of command. (c) Return to State Status. As much as practical, National Guard members, units, and organizations ordered to active duty must return to their state National Guard status once relieved from that active duty.