African American adolescent females are disproportionately affected by the HIV epidemic. Recent findings suggest that gender- and culturally appropriate HIV prevention interventions can significantly reduce HIV-associated sexual risk behaviors among this vulnerable population. Currently, there are no evidence-based interventions (EBIs) for this vulnerable subgroup. Thus, interventions specifically tailored for this subgroup are urgently needed. Effective interventions that reduce HIV risk behaviors remain one of the most powerful tools in curbing the HIV epidemic. The selected intervention (Horizons) was adapted using a coordinated and systematically guided adaptation process based on the ADAPT-ITT framework. This article serves as a starting point to support using the ADAPT-ITT model, which was beneficial when using an EBI in an alternative setting than originally created. Using this prescriptive method for adapting Horizons for incarcerated young girls proved to be a time- and cost-effective method.