INTRODUCTION: Incarcerated individuals with opioid use disorder experience high rates of opioid-related mortality upon release. Buprenorphine and methadone are effective at reducing mortality rates in this population, but evidence for extended-release naltrexone is mixed. We evaluated a comprehensive jail-based program in Massachusetts (MATADOR 2.0), which combined extended-release naltrexone and recovery navigator support before and after release. METHODS: We examined opioid-related mortality up to one year after release among participants in MATADOR 2.0 using propensity-matched comparison groups and Cox proportional hazards models accounting for repeated treatment attempts and competing risks. Additionally, we performed a sensitivity analysis limiting the hazards model to the first treatment attempt. Lastly, we examined predictors of treatment completion using logistic regression. RESULTS: There was no difference in opioid-related mortality between program participants and a propensity-matched comparison group (adjusted hazards ratio (aHR) 0.58, 95 % confidence interval (CI): 0.28-1.22). However, the sensitivity analysis found a decreased risk in the intervention group (aHR = 0.47, 95 % CI: 0.23-0.96) compared to a propensity-matched comparison group. Individuals who completed the program were less likely to experience an opioid overdose death (aHR=0.25, 95 % CI: 0.08-0.72) compared to a propensity-matched comparison group. Individuals who underwent a polysubstance detoxification upon incarceration were less likely to complete the program (adjusted odds ratio=0.32, 95 % CI: 0.17-0.59). CONCLUSION: Extended-release naltrexone delivered within a comprehensive care model including recovery navigator support may be an effective option to reduce opioid-related mortality for incarcerated individuals who choose not to initiate opioid agonist treatment, but more research is needed.