17 pages. June 2022. Includes bibliography. Peer support workers, also known as peers, are individuals with lived experience who have sustained recovery from a mental or substance use disorder, or both. The assist others entering or in recovery with reducing the recurrence of symptoms, more commonly known as relapse. This advisory discusses the role of peer support workers and models of peer support services that are available to assist individuals who are experiencing a crisis, including recovery. Peer support services are a vital component of crisis care.