heightened focus in the field on trying to bridge this research-to-practice gap, many researchers have experienced more than a modicum of success in facilitating teachers' use of research-based methods (Abbott, . We now know more about how to conduct professional development programs that support teachers' sustained implementation of new practices than we did a decade ago. Rather than the "sit and get" standalone workshops more prevalent in the past, successful efforts have focused on providing long-411 ABSTRACT:The purpose of this research was to "scale up" the implementation of four research-based practices in inclusive classrooms. Twenty-nine teachers from six elementary schools participated in a 2-week professional development program and received extensive follow-up support from researchers throughout the school year. Our objective was to better understand the barriers and facilitators experienced by teachers determined to be high implementers (9), moderate implementers (9), and low implementers (11). Data sources included interviews, teacher logs, and classroom observations. Teachers across implementation levels lamented a lack of instructional time. Yet how teachers dealt with barriers differed. High-implementing (HI) teachers reported administrative support as their top facilitator, while five moderate-implementing (MI) teachers described a lack of administrative support. School effects were noted.