This article traces the history of the Recovery Community Services Program (RCSP) from its inception in the Substance Abuse Mental Health Services Administration/Center for Substance Abuse Treatment (SAMHSA/CSAT) 1998 vision of communities of recovery engaged in the public dialogue about addiction, treatment, and recovery through the 2002 programmatic refocus onto the provision of social supports for recovery, designed and delivered by people who share the experience of addiction and recovery, that is, peers. It focuses on the role of peer-to-peer recovery support services in an evolving recovery-oriented system of care, lessons learned as the grant program has matured, and continuing challenges in this latest chapter of the ongoing history of the relationship between communities of recovery and formal systems of care. Following articles represent how these principles are embodied in RCSP communities across the nation.