The study examines a new SAMHSA rule that allows prisons and jails registered as hospital/clinic facilities to stock and dispense methadone to patients who have both opioid use disorder and another health condition. Three state prison systems plan to adopt this approach and participate in a collaborative learning program to support implementation. Researchers will track progress and challenges through surveys and interviews and analyze health records to see how in-prison methadone availability affects treatment initiation, continuity before release, and post-release outcomes such as continued treatment and hospitalizations. They will also assess the costs and financial impact of the hospital/clinic model compared with relying on methadone from opioid treatment programs