The purpose of each reserve component is to provide trained units and qualified persons available for active duty in the armed forces, in time of war or national emergency, and at such other times as the national security may require, to fill the needs of the armed forces whenever more units and persons are needed than are in the regular components.
Structure US Code
Subtitle E— Reserve Components
PART I— ORGANIZATION AND ADMINISTRATION
CHAPTER 1003— RESERVE COMPONENTS GENERALLY
§ 10101. Reserve components named
§ 10102. Purpose of reserve components
§ 10102a. Deployment prioritization and readiness of Army components
§ 10103. Basic policy for order into Federal service
§ 10104. Army Reserve: composition
§ 10105. Army National Guard of the United States: composition
§ 10106. Army National Guard: when a component of the Army
§ 10107. Army National Guard of the United States: status when not in Federal service
§ 10108. Navy Reserve: administration
§ 10109. Marine Corps Reserve: administration
§ 10110. Air Force Reserve: composition
§ 10111. Air National Guard of the United States: composition
§ 10112. Air National Guard: when a component of the Air Force
§ 10113. Air National Guard of the United States: status when not in Federal service