This project aims to complement HEAL's Justice Community Opioid Innovation Network (JCOIN) initiative by focusing on post-release recovery in six county jails in Illinois with the goal of increasing linkage to and retention in community-based treatment with medication for opioid use disorder (MOUD) and reducing both opioid use disorder (OUD) relapse and criminal recidivism over two years. The study builds upon the platform of prior research demonstrating the effectiveness of the Recovery Management Checkups (RMC) intervention. To date, three randomized controlled trials conducted by the study investigators have demonstrated RMC's effectiveness by increasing treatment engagement and retention, re-linking recovering patients to treatment when indicated, and improving their health, psychosocial functioning, and other outcomes. Across these studies, relative to controls, participants in the RMC condition reported more treatment initiation, more days of treatment received, fewer days of substance use, and fewer health symptoms. In the proposed study, an adapted version of the RMC (RMC-A) will build upon the core components of the RMC by tailoring the checkup frequency to the individual's assessed need for treatment over time. The goal of the proposed experiment is to compare linkage and retention rates as well as public health and public safety outcomes of 750 male and female offenders who will be randomly assigned to 1 of 3 groups upon their release from jail: a) re-entry as usual (control), b) the original RMC, and c) a RMC-Adaptive version in which the frequency and content of checkups will be based upon the participant's ongoing progress as assessed by a set of indicators of treatment need. The study will be conducted in collaboration with 6 county jails in Illinois, and their local OTPs that currently provide pre-release MOUD to offenders with OUD. Pre-release participants will be screened for history of OUD and eligibility for MOUD following usual procedures. All participants will receive quarterly research follow-up assessments. Data sources include interviews with standardized measures, urine tests, treatment records to verify treatment received, recidivism, death records, and cost accounting. Research staff will administer the 25-minute Global Appraisal of Individual Needs - Quick (GAIN-Q3) and several supplemental scales at study enrollment, and again quarterly over 24 months post-study enrollment. The GAIN-Q3 includes 8 primary domains: 1) background, 2) school problems, 3) work problems, 4) physical health, 5) sources of stress, 6) HIV risk behaviors, 7) substance use, and 8) crime and violence. The response set captures the recency of these symptoms (life time, past year, past 90 days, past month) and treatment involvement, then the frequency (days) of behaviors/treatment utilization in the past 90 days. The GAIN-Q3 includes a behavioral health screener, health care utilization measures, measures of days of methadone treatment, heroin and other opioid use, days of other types of treatment, and other substance use. The GAIN-Q3 will be supplemented with the Quality of Life measure from the Patient Reported Outcomes Measurement Information System (PROMIS) - R. Data will be collected via a cloud-based computer program that controls ranges and skip-outs and identifies major inconsistencies for interviewers. All interviewers will receive extensive training and monitoring to ensure data quality. At the time of each in-person research assessment, on-site urine screens will be conducted with DrugCheck cups and fentanyl test strips using an immunoassay for rapid qualitative results based on SAMHSA-standard cutoffs for methadone and opiates/morphine in general, as well as specific tests for fentanyl, Oxycodone, and other substances. Research staff will be trained on a protocol that minimizes false negatives consistent with NIH's PhenX common data platform. The intervention focuses on improving elements in the OUD service cascade that have historically presented challenges, i.e., successful treatment linkage, engagement, and retention in community-based treatment post-release. With its emphasis on adapting an existing evidence-based intervention (RMC) to reduce high drop-out and increase retention in treatment with MOUD, it places individuals with OUD at lower risk for relapse, overdose, and death. The RMC model also proactively addresses the well-documented chronic cyclical nature of addiction, whereby individuals transition between being in treatment, in the community using, incarcerated, and in recovery. Findings from the study may help to target resources to those with demonstrated need, and reduce the intervention burden on those with lower need, thus resulting in an improved overall effectiveness and cost-effectiveness of RMC checkups.