Early childhood special education teachers require training and support in implementing function-based intervention for challenging behavior. Yet, teacher professional development practices are not universally effective, and teachers may benefit from differentiated supports. The purpose of this study was to pilot and evaluate a multilevel approach to teacher professional development for function-based intervention. The multilevel approach included behavioral skills training, practice-based coaching, and teacher self-monitoring and was evaluated using a multiple baseline across participants single-case research design. Results demonstrated that while all teachers benefited from the professional development, teachers required different levels of support within the multilevel approach. These findings support a growing body of work suggesting that teachers may require varying levels of support to implement evidence-based practices. (author abstract)