10 U.S.C. § 12304 — Selected Reserve and certain Individual Ready Reserve members; order to active duty other than during war or national emergency

(a) Authority: Despite section 12302(a) or any other law, if the President decides it's necessary to add to the active forces, or to give the assistance described in (b), the President can authorize the Secretary of Defense (and the Secretary of Homeland Security for the Coast Guard, when it's not part of the Navy) to order, without the members' consent, any unit or unassigned member of the Selected Reserve, or any Individual Ready Reserve member in the mobilization category designated essential, to active duty^* for up to 365 straight days.
(b) Support for certain emergencies: This authority includes ordering a unit or member to active duty to help respond to an emergency involving the use or threatened use of a weapon of mass destruction, or a terrorist attack (or threat) in the U.S. that results or could result in major loss of life or property.
(c) Cyber incidents: When the Defense Secretary (or Homeland Security Secretary for the Coast Guard) decides it's necessary to augment forces to respond to a "covered incident," that Secretary can order, without consent, Selected Reserve units or members to active duty for up to 365 straight days.
(d) Limitations: (1) No unit or member can be ordered up under this section to perform functions under chapter 13 or section 12406, or -- except under (b) or (c) -- to help respond to a serious natural or manmade disaster. (2) No more than 200,000 Selected Reserve and Individual Ready Reserve members total can be on active duty under this section at once, and no more than 30,000 of those can be from the Individual Ready Reserve. (3) A unit or member can't be ordered up under (b) unless the President determines the emergency has exceeded, or will exceed, what local, state, and federal civilian agencies can handle.
(e) Members ordered up under this section don't count toward authorized active-duty or in-grade^* strength limits under this or any other law.
(f) The Defense Secretary and Homeland Security Secretary must set policies and procedures to carry this out for the forces under their jurisdiction.
(g) Whenever the President uses this authority under (a) or (c), the responsible Secretary must report to Congress in writing within 24 hours, explaining the circumstances and the anticipated use of the units or members.
(h) Duty ordered under (a) ends by order of the President or by law; duty ordered under (c) ends by order of the responsible Secretary or by law.
(i) Nothing here changes or limits the War Powers Resolution.
(j) In deciding which Selected Reserve and Individual Ready Reserve members get ordered up without consent, officials must weigh: (1) length and type of past service, to spread out danger exposure fairly; (2) how often the member has already been called up; (3) family responsibilities; and (4) whether their job is necessary for national health, safety, or interest. The Defense Secretary must set policies for this.
(k) Definitions: A "covered incident" is a cyber incident (or breach involving personal data) hitting a Defense or Homeland Security system that the responsible Secretary finds is likely to seriously harm national security, foreign relations, the economy, public confidence, civil liberties, or public health and safety; a cyber incident (or group of incidents) the President finds likely to cause that kind of harm; or a "significant incident" declared under section 2233 of the Homeland Security Act of 2002. "Individual Ready Reserve mobilization category" has the meaning in section 10144(b). "Weapon of mass destruction" has the meaning in the Defense Against Weapons of Mass Destruction Act of 1996.