Methadone has been hard to access in prisons and jails due to federal rules limiting its use to specific treatment programs. A new rule from the Substance Abuse and Mental Health Services Administration (SAMHSA) specifies that carceral facilities registered as “hospital/clinic” facilities can stock and dispense methadone, provided patients have another health condition in addition to opioid use disorder (OUD). The study involves three state prison systems that are planning to use this new approach to expand methadone access and to start a collaborative learning program to help these prison systems and other carceral systems implement these new rules, tracking their progress and challenges through surveys and interviews. Investigators are also analyzing records of people diagnosed with OUD, to identify how the availability of methadone in prisons affects the start and continuity of treatment before release. They examine post-release outcomes including continued treatment and hospitalizations and assess the financial impacts of implementing this hospital/clinic designation, comparing it to in comparison with the status quo of methadone provision via opioid treatment providers.