In this replication and extension study, we examined the effects of educators’ participation in practice-based professional learning (PBPL) to design, implement, and evaluate functional assessment-based interventions (FABIs). We randomly assigned school-site teams (k = 69; N = 342) to cohorts trained by either university or state technical assistance providers. In a randomized cluster design, we replicated and extended previous research by examining procedural integrity, participant learning outcomes, completion and quality levels of PBPL-FABI activities, and student outcomes. Results provide additional evidence to support PBPL-FABI in improving school-site teams’ knowledge, confidence, use, and initial evidence for its scalability, as evidenced by state technical assistance providers’ high implementation levels comparable with university trainers. We conclude with a discussion regarding PBPL-FABI and considerations for future research.