Community-building is not just about creating or defining a new work for teachers to do collaboratively. It is also about changing a school’s professional culture. The effectiveness of a community facilitator depends upon the individual’s skills in this role and upon the authority they have or are granted to lead school change. Once legitimized as a leader of change in the school, skilled facilitators can establish new norms of teaching—reflection on teacher with colleagues and co-designing interventions to better meet student needs. Community facilitators create a focus, rationale, and vehicle for teachers to depart from private classroom practice.