These teacher comments refer to the impact of the staff development teacher, the “teachers’ teacher” in each of the 199 schools in Montgomery County Public Schools in Maryland. The staff development teacher facilitates the evolution of a school-based professional learning community focused on improving teaching and learning by being a catalyst for teacher change and reflection. The staff development teacher has become a linchpin resource charged with facilitating school-based professional learning communities that improve teaching and learning. THE BEGINNING The district’s initial challenge was transforming more than 200 talented and knowledgeable teachers into a cadre of skilled staff developers who were on the same page systemwide, able to communicate consistent messages and practices in their schools, and to help teachers implement change. These teacher leaders