Children's social and emotional skill deficits can be predictors of a lifetime of academic and behavioral challenges and mental health concerns. Young children with challenging behaviors are at a higher risk for substance abuse and school failure. Behavior coaching is a current focus in many schools and is being utilized to support school-wide systems and teachers in relationship to students with behavior and mental health concerns. The purpose of this descriptive quantitative study was to investigate the impact of interdisciplinary collaborative behavior coach training for school counselors, social workers, and psychologists in a Midwest suburban school district. Interdisciplinary collaborative behavior coach training is a product of at least two partners of expertise using the interdisciplinary collaboration model. This model consists of five core components including interdependence, newly created professional activities, flexibility, collective ownership of goals, and reflection on process. In order to establish and maintain a successful Multi-tiered Systems of Supports for Behavior (MTSS-B) implementation, leadership teams must develop a behavior coaching network. Behavior coaching encompasses two different types of coaching styles including systems coaching and collaborative coaching. Behavior coaches support teachers and administrators by providing tier one social and emotional learning (SEL) curriculum professional development, leading the collaborative problem-solving process, and prompting reflective thinking about teaching practices to change student behavior. Behavior coaching was a new responsibility for school counselors, social workers, and psychologists; therefore, examining the impact of professional learning brought awareness to areas of strength and weakness of behavior coaching. Analyzing impact can be useful in order to improve an intervention, in this case behavior coaching training sessions, and to make decisions about continuing, replicating, and expanding the training sessions. The results of this study informed future professional development in the research district. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]