Inside StART: Implementation of Novel Strategies for long-acting ART - PROJECT SUMMARY/ABSTRACT People with criminal legal involvement (CLI) are disproportionately impacted by HIV. One in seven people living with HIV (PWH) enter a carceral setting each year and HIV prevalence among people with CLI is up to three times greater than the general adult population. Co-occurring conditions such as mental illness, substance use, and homelessness are also disproportionately represented among the CLI population, increasing the risk of HIV acquisition, transmission, and disruption in HIV care. Correctional facilities, such as jails, can serve as intervention points by providing HIV testing and treatment that may be less accessible to these individuals in the community. While HIV care outcomes (e.g., HIV viral suppression) improve in the period immediately following release due to (re)initiating patients on antiretroviral treatment, these gains are tenuous as patients are often disengaged from community-based HIV primary care and non-adherent to anti- retroviral medication. Furthermore, incarceration itself can be disruptive to the continuity of HIV care for PWH in part due to interruption of medical insurance. Research is critically needed to understand the nuanced dynamics of care continuity for PWH-CLI, the role of contextual factors in enabling post-incarceration HIV care, and how to consistently engage this population in HIV care post-incarceration and maintain viral suppression. While multiple interventions have been deployed at the local and state level to improve care engagement following release from jail, such as care navigation, transitional care coordination and pre-release enrollment in Medicaid, novel modalities for antiretroviral treatment (ART), such as long acting injectables (LAs), present a promising solution to maintaining viral suppression and reduce clinic visits, even among those with adherence challenges. However, a concern for populations with suboptimal care engagement is that inconsistent administration of LAs can lead to viral resistance and viral rebound. The primary goal of this research program – based in San Francisco, California, a priority jurisdiction for Ending the HIV Epidemic – is to use a mixed- methods approach to understand current care outcomes for PWH-CLI and pilot test administering the novel modality of LA-ART to improve viral suppression rates in this group. Leveraging a unique longitudinal cohort of patient-level integrated data of PWH-CLI electronic health records and social service utilization and patient access through our specialty re-entry clinic for PWH-CLI released from jail, the research goals of this study are to: (1) model and characterize trajectories of care utilization to identify care coordination opportunities, (2) model the impact of post-release contextual factors on HIV care engagement, and (3) conduct a pilot study to initiate PWH-CLI on LA-ART during their jail incarceration and evaluate implementation outcomes, mapped to the RE-AIM framework, to assess a path to successful delivery of the model. The evidence generated from this work will inform novel interventions for re-engagement and establishing continuity of care for PWH-CLI.