Improving Outcomes and Equity for Released Prisoners with SUD: Trajectories of Participation in Pre-Release and Post-Release MOUD, Peer Navigation, and Outcomes - PROJECT ABSTRACT Following prison release, individuals with substance use disorders (SUDs) experience high rates of return to substance use and overdose. Justice-involved people account for an important part of the population with high overdose risk; therefore, a high priority for national overdose prevention strategies is to identify and implement better interventions to support them in safe re-entry. Promising strategies include pre-release medication for opioid use disorder (P-MOUD) and peer navigation (PN). To assess implementation and effectiveness, and support translation across the nation's prison systems, it is vital to assess uptake and re-entry outcomes; identify what components are effective, for whom, how and why, and for how long; document barriers and facilitators to program success; and assess PN's effectiveness in supporting post-release MOUD retention and recovery. New Jersey has implemented both interventions at large scale across all of its 11 prisons, with more than 4,000 individuals receiving P-MOUD and 2,500 PN through 2022, creating a unique research opportunity to develop and disseminate knowledge on these interventions when implemented systemwide as standard practice. Use of richly linked clinical and administrative data, for an unprecedently large cohort of individuals with SUD released from 2016-2027, will provide power to assess interactions among interventions and their effects in key subgroups, with longitudinal follow-up to examine long-term outcomes, using state-of-the-art analytic models to produce robust estimates across subgroups of concern. Innovative mixed-methods strategies, leveraging linked data and first-hand experiences, will assess patterns and disparities in pre-release MOUD and PN participation; retention in services during re-entry; and recovery outcomes among participants and non-participants. In-depth interviews during re-entry will document participants' experiences with the programs, in the context of their broader re-entry experience, their decisionmaking about MOUD and illicit drug use, and recovery barriers and facilitators. Interviews with policymakers, providers, and other stakeholders will elicit their perspectives on implementation and generate evidence to support cross-state translation. Among releasees with SUDs, the study will: 1.) examine patterns/predictors of pre- and post-release MOUD and PN; 2.) examine recovery outcomes over the re-entry period and their relationship to PN and MOUD, separately and jointly, utilizing innovative event history analysis strategies incorporating propensity scoring and machine learning strategies; and 3.) utilize qualitative interviews to elicit experiences of implementation and adaptation of PN and MOUD from the perspectives of participants and multiple other stakeholders. Implementation and dissemination will be guided by a Stakeholder Advisory Board including persons with lived experience, providers, correctional leaders, prisoner rights advocates and experts. This study of NJ's innovative, large- scale interventions provides a unique opportunity to build knowledge that can help save lives and improve outcomes during community re-entry, with important implications for intervention in other at-risk populations.