This paper provides outcomes of a study examining the effectiveness of a year-long professional development training series designed to support in-service educators in learning a systematic approach to functional assessment-based interventions developed by Umbreit and colleagues (2007) that has met with demonstrated success when implemented with university supports. Forty-eight educators attended a 4-day, practice-based professional development series, with coaching and applied practice occurring between sessions. Participants completed pre- and post-training surveys to evaluate their perceived knowledge, confidence, and usefulness as well as actual knowledge of 15 concepts and strategies addressed in the training series. Outcomes as well as implications for professional development to support in-service teachers and school personnel in learning how to design, implement, and evaluate functional assessment-based interventions are offered. Results indicated statistically significant improvements in each concept and strategy measured. Findings are discussed in light of noted limitations, with recommendations offered to improve subsequent professional development efforts.