Authored by Stephanie Hirsh, this white paper for Arabella Philanthropic Advisors is one of several on school reform topics by noted authors. New assessment systems will provide teachers with significant new opportunities to guide all students toward college and career readiness. To benefit from such assessments, states will need to be more thoughtful than they have been in the past about conceiving, organizing, managing, implementing, and evaluating effective professional development. The paper offers eight recommendations to help rebuild professional development infrastructure to support these systems.