Context: This study addresses recent changes in professional development policy, practice, and theory, in which professional development has increasingly become continual, collaborative, and school based. We consider both traditional notions of structure and content as well as context in developing a more complete understanding of professional development for today's teachers. Purpose: We conducted this study to understand more fully the delivery of school-based professional development within a high-stakes accountability context. We build on the accountability, professional development, and school context literature and expand the explanatory framework to include teacher experience with, and use of, school-based professional development in instructional practices. Research Design: We conducted case studies of professional development in three elementary schools with varying levels of pressure to make adequate yearly progress. Although these three school sites operated within the same federal, state, and district policy contexts, the school contexts varied considerably. We focused in particular on professional development around short constructed responses, a form of paragraph writing required for the state exam. Conclusions: We argue that school leadership, culture, and resources, as well as the structure and content of professional development, filter policy initiatives before they ultimately shape teacher learning experiences. Although high-stakes accountability policies increased the quantity of professional development, the quality of teacher learning opportunities depended on the context in which it was delivered.