Teacher leadership is increasingly recognized as a promising strategy to improve the quality of instruction in U.S. schools. Despite the rising number of teacher leadership programs in the country, there is a paucity of knowledge about the work that teacher leaders (TLs) engage in, how educators experience teacher leadership and the impacts of these efforts on teacher leaders themselves and on districts, schools, teachers, and students. In response, the Nellie Mae Education Foundation (NMEF) supported the Consortium for Policy Research in Education (CPRE) to investigate educators' experiences with teacher leadership and describe the impacts of this improvement strategy.