Abstract Health literacy refers to the skills needed to effectively access, understand, and use health resources. Inadequate health literacy annually costs the U.S. $100-$200 billion and is observed among justice involved adults (JIA)—a group of ~20 million U.S. persons who are disproportionately non-elderly and African American, Black, and Hispanic due to systemic racism and over-policing. JIA face numerous barriers in accessing healthcare which contributes to a high, lifelong burden of chronic and infectious disease. Healthcare access is defined as 1) having health insurance coverage, 2) having a regular source of care and 3) obtaining healthcare in a timely manner. Health literacy interventions for JIA are critically needed but are unavailable and NIH- funded research that is inclusive of JIA is sorely lacking. This timely study addresses these gaps. We have obtained promising results from a pilot study of a novel intervention that seeks to build JIA’s health literacy and improve their healthcare access. Therefore, we propose to implement a longitudinal mixed-methods randomized clinical trial (RCT) to assess the impact of the UCSD RELINK coach-guided health literacy intervention vs. a self-study control group on JIA’s healthcare access. To achieve this aim, 300 JIA ages 18-50 will be recruited in San Diego, CA and randomized 1:1 to the Treatment Group (i.e., coach-guided health literacy intervention) or the Control Group (i.e., self-study of the intervention). Researchers will assess JIA’s use of healthcare within 6 months at 6-month follow-up as the primary outcome. Secondary outcomes include assessing maintenance of healthcare access at 12-month follow-up. We hypothesize that participants in the Treatment Arm will exhibit improvements in all healthcare access measures as compared to Control Group participants (Aim 1) and specifically, that they will be more likely to report healthcare use within 6 months than the control group. For Aim 2, we will conduct longitudinal individual interviews at 6- and 12-months to assess JIA’s satisfaction with the intervention; healthcare attitudes, self-efficacy for healthcare use; factors impacting maintenance of healthcare access over time; perceived contribution of the intervention to health and well- being; and diffusion of the intervention to JIA’s social contacts. To achieve this aim, we will conduct semi- structured qualitative interviews with 40 purposively sampled participants (20 per intervention arm) who reported healthcare access barriers at baseline. This study is timely and may inform health literacy interventions for JIA, policies to build health literacy among JIA in institutional and community settings, and the service delivery models for JIA. The proposed intervention has great potential for increasing health literacy among JIA and thus improving the well-being of this sizeable and underserved community. Findings from this study may also have relevance for interventions seeking to build the ...