Despite claims that school districts need flexibility in teacher assignment to allocate teachers more equitably across schools and improve district performance, the power to involuntarily transfer teachers across schools remains hotly contested. Little research has examined involuntary teacher transfer policies or their effects on schools, teachers, or students. This article uses administrative data from Miami-Dade County Public Schools to investigate the implementation and effects of the district's involuntary transfer policy, including which schools transferred and received teachers, which teachers were transferred, what kinds of teachers replaced them in their former schools, and how their performance—as measured by their work absences and value-added in math and reading—compared before and after the transfer. We find that, under the policy, principals in the lowest performing schools identified relatively low-performing teachers for transfer who, based on observable characteristics, would have been unlikely to leave on their own. Consistent with an equity improvement, we find that involuntarily transferred teachers were systematically moved to higher performing schools and generally were outperformed by the teachers who replaced them. Efficiency impacts are mixed; although transferred teachers had nearly two fewer absences per year in their new positions, transferred teachers continued to have low value-added in their new schools.