Background. A significant and growing population of young people are acquiring and living with HIV in the US. An estimated >12,200 adolescents were diagnosed with HIV infection in 2010, a 22% increase since 2008(1). Although HIV can be managed with ongoing antiretroviral therapy (ART), exceptionally high levels of adherence are required. Our recently published systematic literature review found that of the 21 articles published that reported data on medication adherence in HIV infected adolescents, seven described pilot interventions to enhance medication adherence; and only two utilized education / counseling sessions to promote adherence skills-building – a component that has shown to be necessary to improving adherence among HIV-infected adults. To our knowledge, there are no demonstrated efficacious ART adherence interventions for HIV infected adolescents to date. This is particularly concerning given that overall rates of adherence among adolescents is generally suboptimal. Overview of Proposal. This proposal is culmination of 6 years of formative work with this population, including conducting two pilot randomized controlled trials (RCT). The current study is to test the efficacy of a stepped-care “adaptive” ART adherence intervention (“Positive STEPS”) for HIV infected adolescents, ages 16 to 24. Stepped care is a healthcare delivery model in which the least resource intensive part of an intervention is delivered first, and only those who do not improve then receive the high intensity, more resource intensive part of an intervention. Conceptual Model. The conceptual model is based on our formative work that led to the development of a theoretically-driven intervention curriculum (“Positive STEPS”), grounded in the social and contextual realities of HIV infected adolescents. Our intervention begins with 2-way daily text messaging aimed at improving ART adherence. For many adolescents (over 1/3 from our pilot RCT), text messaging is not sufficient to overcome the barriers to ART adherence. These individuals will then also receive the more intensive component based on general principles of cognitive-behavioral therapy. Informational, problem solving, and cognitive-behavioral “steps” are addressed over 5, in-person, intervention-counseling sessions (incorporating digital video vignettes that are specific to the adherence challenges faced by adolescents). Overview of Research Plan. 192 HIV infected adolescents, aged 16 to 24, and prescribed ART will be recruited in two major U.S. cities with excellent access to and research experience with the population. Participants will be equally randomized to: (1) “Positive STEPS” – a stepped care, adherence intervention with integrated technology and counseling; or (2) Standard of Care comparison group. Participants will be followed for one-year post-randomization. The primary outcomes are improvements in measures of ART adherence (i.e., Wisepill, HIV viral load, and self report); secondary outcomes inclu...