This is a single group, one arm trial in which participants (youth living with HIV aged 16-25 years who are current residents of South Carolina) will receive access to a mobile health (mHealth) intervention called MindBodyU that is delivered via smartphone application (app) and designed to improve engagement in care, medication adherence, and psychosocial wellbeing. The intervention includes app-based learning content, daily prompts for medication adherence, appointment reminders, behavioral health symptom tracking, ability to connect with content experts, and ability to seek feedback/support from other users. Participants will be instructed to use the intervention over a 12-week period, and will complete surveys at baseline, 12-weeks, and 6-months to assess for feasibility and acceptability of the intervention, as well as participants' engagement/retention in care, adherence to antiretroviral therapy, viral suppression, and psychosocial wellbeing.

The MindBodyU app is an mHealth intervention that was developed based on input from youth living with HIV, HIV providers, and community-based organizations. The app includes multiple features designed to promote HIV care engagement, medication adherence, and psychosocial wellbeing for youth living with HIV in South Carolina. Users of the app will have the opportunity to create anonymous profiles in which they can access resources related to HIV, behavioral health, sexual health, and other social determinants of health. The app also has features that enable youth to monitor and track health behaviors (e.g., appointment reminders, medication adherence), message healthcare professionals with general health questions, and engage in moderated online forums with HIV providers and other YLHIV.

Study retention will be measured by how many participants are retained in the study at 12-weeks (i.e., complete the 12-week follow-up. Investigators will define good retention as at least 70% of participants retained in the study at 12-weeks. Study retention will be viewed as one aspect of feasibility of the MindBodyU intervention, which refers to whether adolescents and young adults will use the intervention in their real-world environments.

This outcome is acceptability of the MindBodyU Intervention, which refers to whether adolescents and young adults find the intervention to be likable, enjoyable, engaging, and culturally appropriate. Acceptability will be measured by the Acceptability of Intervention Measure (AIM), and operationalized as a mean score of 3 or more on 5-point Likert scale for the following items: 'MindBodyU meets my approval', 'MindBodyU is appealing to me', and 'I like the MindBodyU app'. It will also be measured by participant scores on the item, 'The MindBodyU app aligns with my values' and 'The MindBodyU app is a good fit for me' (i.e., score of 3 or more on 5-point Likert scale).

This outcome assesses participants' self-reported adherence to antiretroviral therapy (ART). The outcome is measured by the following items:

1. Are you currently taking medications for HIV (also called antiretroviral therapy or ART)? (Yes, No, I Don't Know)
2. In the last 30 days, on how many days did you miss at least one dose of any of your HIV medications (ART)? I missed ______ days out of the last 30 days (0-30)
3. In the last 30 days, how often did you take your HIV medication in the way you were supposed to? (Never, Rarely, Sometimes, Usually, Almost always, Always)
4. In the last 30 days, how good a job did you do at taking HIV medication in the way you were supposed to? (Very poor, Poor, Fair, Good, Very good, Excellent)

This outcome evaluates youths' experiences, feelings, and opinions about HIV-related stigma. The outcome is measured by 12 items that are answered on a 4-point Likert scale (strong disagree to strongly agree) and assess participants' feelings and behaviors related to stigma (e.g., feeling like they have to keep their HIV a secret, feeling bad about themselves due to their HIV status).