We use a unique administrative database from the state of Florida to provide the first evidence that promotion and other job reassignments within school districts are systematically related to differences in teacher effectiveness in raising student achievement. We follow the career paths of a cohort of almost 25,000 classroom teachers during the 2001-2002 school year for seven subsequent years. Our results confirm that effective teachers are more likely to become assistant principals or principals and less likely to be reassigned to a low-stakes teaching position. The tendency of highly effective teachers to continue teaching in high-stakes grades and subjects is strongest in schools receiving low ratings from the state's school accountability system. Teachers entering the principal track experience a large increase in annual earnings, but the share of teachers promoted in this way is small enough that future compensation remains largely unrelated to effectiveness for teachers as a whole.