In an event where Congress declares a state of war or national emergency, the Secretary of Defense can authorize the Secretaries of the Army, Navy, and Air Force to recall retired military personnel. Retirees may be recalled up to age 64 for general officers, age 62 for Warrant Officers, and age 60 for all others. Retirees are placed into one of three categories for recall purposes.

Category I (usually called first) includes retired servicemembers who meet the age and grade criteria, were not retired for permanent disability, have a US address, and have been retired fewer than five years.

Category II (usually called after Category I) includes servicemembers with the same qualifications as the first category, but retired for more than five years.

Category III includes all other retired servicemembers, including permanently disqualified disability retired servicemembers. Category III will generally not be recalled. A member of the Retired Reserve who returns to active duty may only receive one type of payment. Presently, there has been no indication that recall of military retirees is even being considered.