Abstract: Young trans women experience a number of psychosocial challenges including discrimination, prejudice, stigmatization, and social/economic marginalization, which stand as obstacles to linkage and retention in HIV care and ART medication adherence. Due to these challenges, and their often transient nature, a text-messaging HIV intervention that is easily accessible, culturally competent, private and portable is a particularly salient method for engaging and retaining young trans women in HIV care. This project utilizes a text-messaging intervention to improve engagement, retention, and health outcomes along the HIV Care Continuum, with the desired outcome of viroligical suppression, among HIV-positive young trans women, aged 18-34, who are not linked to care, or not retained in care, or not prescribed ART, or nonadherent to ART, or not virologically suppressed. Over the course of the 90-day intervention, participants receive 270 theory-based text messages that are targeted, tailored, and personalized specifically for HIV-positive young trans women; participants receive three messages per day in real-time within a 10-hour graduated and automated delivery system. The text-message content is pre-written along the HIV Care Continuum (i.e., HIV positivity/physical and emotional health, linkage/retention in care, ART adherence/viral load suppression) and is based on three proven theories of behavior change (i.e., Social Support Theory, Social Cognitive Theory, and Health Belief Model). Following screening for eligibility, informed consent, and baseline assessment, participants are randomized into one of two conditions: Group A: Immediate Text Message Intervention Delivery (ID, n=60); or, Group B: Delayed Text Message Intervention (DD, n=60) whereby participants are delivered the text-messaging intervention after a delayed 90-day period. Participants in both groups receive the exact same 90-day text-messaging intervention. Following the 90-day theory-based, trans-specific text-messaging intervention, participants may opt in/opt out of continued weekly post-intervention messages for ongoing retention and engagement support derived from the HRSA-funded UCARE4LIFE library. The randomized two-group repeated measures design assesses participants at 3-, 6-, 12-, and 18-months post-randomization to determine observed intervention effects and longitudinal intervention effects.