The goal of this study is to conduct a Type 1 hybrid effectiveness-implementation study of seven jails in Massachusetts that deliver all FDA-approved MOUDs (naltrexone, buprenorphine, methadone) to produce findings with implications for policies for OUD in criminal justice settings. This research will focus on (1) post-release recidivism, overdoses, and MOUD initiation, engagement, and retention, (2) factors that facilitate and impede MOUD delivery in jails and within communities, and (3) cost and economic evaluation of implementation.