Teachers of students with autism spectrum disorder and intellectual and developmental disability (ASD/IDD) report managing challenging behavior as one of the most difficult aspects of their work. Evidence-based practices (EBPs) in behavior management can assist teachers in increasing positive behavior in their students with ASD/IDD; however, evidence suggests that teachers may not use EBP effectively. To support teachers in integrating EBP into their practice to increase positive behavior in their students, we developed Communities of Research and Practice (CoRP). In CoRP, classroom teams and researchers in a Mid-Atlantic U.S. state met monthly to discuss how specific EBP could be combined with teachers’ practical expertise to meet the unique needs of their students. In a pilot randomized controlled trial, no significant pre–post differences were found between CoRP and a business-as-usual comparison group on teacher-reported knowledge and use of EBP; however, CoRP participants reported significantly greater decreases in student conflict and challenging behavior. In addition, participants found CoRP valuable and feasible, with high attendance and completion rates. Implications for reducing the research-practice divide are discussed.