Implementation of Positive Behavior Interventions and Supports (PBIS) is expanding nationally with promising outcomes at the high school level, suggesting that PBIS may be an effective approach for addressing behavior problems, improving attendance, and enhancing school climate. When implemented with fidelity, PBIS serves as an organizing framework for high school social skills instruction, violence prevention, and bullying programs. Despite these promising outcomes, high schools appear to be adopting and implementing PBIS at a slower rate than elementary schools and may struggle to maintain implementation fidelity over time. A variety of factors may contribute to the slower rate of adoption in high schools including the physical size of the campus, larger student populations, and compartmentalized operations. Given these factors, it is important to understand the status of PBIS implementation in high schools. The purpose of this evaluation brief is to provide a description of the current state of PBIS implementation in US high schools, as reflected by data collected by the National PBIS Technical Assistance Center. Specifically, the authors answer the following five questions: (1) How many and what percent of high schools are implementing PBIS?; (2) What is the geographic distribution of high schools implementing PBIS?; (3) How do school characteristics of PBIS high schools compare to national averages?; (4) How are high schools measuring implementation fidelity?; and (5) What are average student outcomes in high schools implementing PBIS?