Background and AimsOffering medications for opioid use disorder (MOUD) in carceral settings can significantly reduce overdose risk. However, it is unknown whether and to what extent individuals in U.S. jail settings continue MOUD once they leave incarceration, and what factors influence treatment continuity.DesignRetrospective cohort study of linked jail-based electronic health records and community OUD treatment claims.SettingNew York City JailParticipantsIncarcerations of individuals with OUD discharged from jail to the community between May 1, 2011 and December 31, 2017ComparatorsReceiving vs. not receiving MOUD (methadone or buprenorphine) at the time of release from jailMeasurementsWe measured continuity of community-based MOUD treatment within one month of release, among those with and without MOUD during release from jail. We tested for effect modification based on MOUD receipt prior to incarceration and assessed factors associated with treatment discontinuation upon re-entry.FindingsOf 28,298 eligible incarcerations, 52.8% received MOUD at release. 30% of incarcerations with MOUD had a community-based MOUD claim within 30 days of release, compared to 7% of incarcerations without MOUD (Risk Ratio: 2.62 (2.44-2.82)). Most (69%) of those with MOUD claims prior to incarceration who received in-jail MOUD continued MOUD in the community, compared to only 9% of those without prior MOUD. Among incarcerations with MOUD at release, those who were younger, Non-Hispanic Black and with no history of MOUD treatment were less likely to continue treatment following release.ConclusionsMOUD maintenance in jail is strongly associated with MOUD continuity in the community upon release. Still, findings highlight a continued gap in MOUD upon-reentry, especially among those who initiate MOUD in jail. In the wake of worsening overdose deaths and troubling disparities, improving continuty of evidence-based care among this population must be an urgent policy priority.