HIV disproportionately impacts minoritized individuals, particularly those of intersectional minoritized identities. Incarceration disproportionately impacts minoritized individuals as well, and increases HIV risk, in part due to its disruption to people's lives, social networks, and access to care. We developed MEPS, a 6-month intervention designed to holistically support HIV prevention in men who have sex with men and transgender women leaving incarceration. We tested MEPS in a 1:1 randomized controlled trial with 208 individuals. All participants received a needs assessment and personalized wellness plan, followed by either standard of care or the MEPS intervention. MEPS integrated support from a Peer Mentor, incentives for engagement in social and health services, and a mobile app. Participants completed baseline assessments and follow-up assessments at 3, 6, and 9 months. We tested for changes in PrEP use using a group-based trajectory model, for changes in HIV and STI testing, frequent substance use and recidivism using logistic mixed models, and for changes in HCV testing and in having a regular place for care using Poisson models. MEPS participants were significantly more likely than control participants to be among those who used PrEP [AOR (95% CI) = 3.8 (1.8, 8.0)]. Recent HIV testing in the MEPS arm remained above 50% over time while decreasing in the control arm, with a significant difference between arms at 6 months [AOR (95% CI) = 3.5 (1.3, 9.5)]. There were no significant differences between arms in the other outcomes. The MEPS intervention was effective in increasing PrEP uptake and HIV testing in people leaving incarceration. Interventions that implement peer mentor support and incentives to encourage service engagement can improve engagement in HIV prevention services among populations that experience unique barriers to care. This study was registered with ClinicalTrials.gov on July 25, 2019 (NCT04036396).