Despite compelling evidence that master's degrees don't systematically make teachers more effective for their students, most US school districts provide a pay premium for them. They should stop, the sooner the better, and states should take the lead in pushing them to do so. Education dollars--whether COVID-19 relief funds or predictable annual revenues--should be spent to improve outcomes for students. In this report, the authors do not attempt to argue that spending on pay premiums for master's degrees is largely wasteful, as study after study has made that case. Instead, they argue that despite the preponderance of evidence against them, the vast majority of districts maintain these pay premiums because the incentives to stop are too weak and those to continue are too strong. State legislatures are best suited to alter the incentives districts face, so the authors offer a range of possible mechanisms states could use to help districts make lasting positive changes in teacher compensation.