This article examines how the history and philosophy of peer support services has shaped current mental health and substance use service delivery systems. The growth of peer-run and recovery community organizations in the changing health care environment are discussed, including issues related to workforce development, funding, relevant policies, and opportunities for expansion. These initiatives are designed to increase access to recovery-promoting services. We conducted an environmental scan and analysis of peer support services within the behavioral health care field in the United States, with particular attention to initiatives of the Substance Abuse and Mental Health Services Administration. Published manuscripts, policy statements, and reports were reviewed. There is abundant and growing literature illustrating how peer support services have become an integral component of behavioral health care systems in many states. Peer support services have the potential to increase access to recovery-oriented services for people with mental and substance use disorders served by the public behavioral health care system. Numerous initiatives in various states are being undertaken to build this workforce. Workforce and financing challenges exist, yet opportunities, including among others those made possible by the Affordable Care Act, will continue to strengthen the peer support workforce within behavioral health service delivery systems. (PsycINFO Database Record