Although there is literature supporting the effectiveness of tertiary behavioral supports, the majority of the studies have been conducted with single-subject designs. The Prevent-Teach-Reinforce (PTR) model is a standardized model of a school-based tertiary intervention. This study reports initial results from a randomized controlled trial to compare whether the PTR model, as implemented by typical school personnel, is more effective than interventions typically used (i.e., services as usual). To date, 245 students in Grades K-8 have been enrolled in the study, and preliminary results show that students who received the PTR intervention had significantly higher social skills and academic engaged time and significantly lower problem behavior when compared with students who received services as usual. Teachers gave high social validity ratings to the intervention. Implications for widescale school adoption are discussed. (Contains 3 tables.)