Maintaining Independence and Sobriety through Systems Integration, Outreach, and Networking – Criminal Justice (MISSION-CJ) is a new approach to providing comprehensive support for individuals with co-occurring mental health and substance use disorder (COD), offering treatment, recovery services, and proactive outreach. Initial tests showed promising results, such as better treatment engagement and improved mental health, along with reduced rates of returning to jail. “Supporting Treatment Access and Recovery in Re-entry (STAR-R)” compares the effects of MISSION-CJ and peer linkage support (PLS). The study aims to show that MISSION-CJ participants engage more in treatment, decrease their substance use, face lower overdose risks, improve their mental health, and have fewer legal issues. The team is also exploring what factors influence these outcomes, such as reducing ties with negative influences and increasing community connections. The study also involves evaluating the costs of implementing MISSION-CJ versus PLS and measuring how cost-effective MISSION-CJ is compared to traditional support methods.