To identify a professional development agenda, we begin in Section 2 with an analysis of how the Framework and NGSS demand real change in K-12 classrooms, exploring the three issues of core ideas, practices and coherence. We identify the central shifts in teaching practices on which professional development must focus if NGSS is to be successful. Then in Section 3, we review the implications of research on professional development, particularly in systemic attempts to change teaching practice, for teaching learning and teacher change of this sort, and consider how an effective PD system could support teaching change aligned with the Framework and NGSS.