This project collected data in communities participating in the Start Strong Initiative, a program to prevent teen dating violence and abuse by teaching 11- to- 14-year-old boys and girls about healthy relationships. Because all Start Strong communities implement a school-based EBP, they represent an ideal laboratory to examine adaptation issues. The study assessed how local context influences adaptation, how practitioners made adaptation decisions, how practitioner characteristics influenced adaptation, and how site and process characteristics related to the types of adaptations made. Findings will contribute to adaptation and implementation science by drawing on the experiential knowledge of expert practitioners.