This paper studies the impacts of teacher pay- for- performance (P4P) reforms adopted with complementary human resource management (HRM) practices on student achievement and workforce flows. Since 2005, dozens of Minnesota school districts in cooperation with teachers' unions implemented P4P as part of the state's Quality Compensation program. Exploiting district variation in participation status and timing, we find evidence that P4P- centered HRM reform raises students' achievement by 0.03 standard deviations. Falsification tests suggest that gains are causal. They appear to be driven especially by productivity increases among less- experienced teachers.