To increase student achievement, schools and districts are hiring teachers as leaders to support peers in improving teaching and learning. Their roles are variously called coach, school-based staff developer, instructional specialist, or program facilitator. These new school leaders are respected as competent teachers, have demonstrated their success with students, and have credibility with both the school’s principal and staff. Yet though many have exceptional teaching skills, they seldom have a deep understanding of working with adult learners, facilitating professional learning, and taking a broad view of the educational system. To develop their relationship with peers, their knowledge, and their facilitation and leadership skills, school-based coaches benefit from initial and ongoing professional development and support from professional associations, state departments of education, districts, and local schools.