We study the relationship between school organizational contexts, teacher turnover, and student achievement in New York City (NYC) middle schools. Using factor analysis, we construct measures of four distinct dimensions of school contexts captured on the annual NYC School Survey. We identify credible estimates by isolating variation in organizational contexts within schools over time. We find that improvements in school leadership, academic expectations, teacher relationships, and school safety are all independently associated with corresponding reductions in teacher turnover. Increases in school safety and academic expectations for students also correspond to increases in student achievement. These results are robust to a range of potential threats to validity, suggesting that our findings are likely driven by an underlying causal relationship. The following is appended: Raw Factor Loadings for School Context Dimensions.