The symposium focuses the nation's attention on a critical policy issue -- the severity of teacher turnover in STEM K-12 mathematics and science -- and identifies evidence-based strategies for addressing this issue. The project proposes a symposium that brings together researchers, policymakers, practitioners and opinion leaders. The meeting is designed to: (1) develop a comprehensive picture of the current knowledge base around teacher turnover; and (2) identify key strategies to improve the retention, quality and diversity of the STEM teacher workforce. The Intellectual merit of this proposal lies in building on the established record of the National Commission on Teaching and America's Future (NCTAF) who have produced several far-reaching reports. The broader impact will be in the identification of policies that can address teacher turnover and retention, disseminate them widely and begin to identify a future research agenda.