Aims: 1) Evaluate the effectiveness of a peer-delivered, community-based education, navigation and support (CENS) intervention to reduce opioid-related risk behaviors; 2) Examine factors that mediate (e.g., knowledge, self-efficacy, self-stigma) and moderate (e.g., mental health, pain/OUD severity, age) intervention effectiveness; and 3) Explore intervention participants' and peer outreach staff perspectives on implementation as well as barriers to and facilitators of intervention effectiveness. The proposed intervention will be delivered by veteran peer outreach workers. The study will recruit 300 veterans with opioid use disorder to participate in a randomized controlled trial. The CENS intervention will engage 150 participants in ongoing educational sessions, healthcare and treatment navigation, and social support (involving both one-on-one and group social integration protocols) designed to improve self-efficacy, reduce self-stigma, increase service and healthcare utilization, and bolster knowledge. This study stands to contribute a timely, culturally-tailored innovation to overdose and HIV/HCV prevention-as-usual that, informed by the theory of triadic influence, directly confronts the social, intrapersonal, and structural-level barriers to opioid-related risk reduction among veterans. Study findings will be of great interest to community-based and civic healthcare organizations that provide overdose and HIV/HCV risk reduction outreach, as well as to agencies committed to improving healthcare engagement among veterans.