Most teachers have tenure protections that constrain dismissal. Some argue that tenure improves recruitment and retention by mitigating the risk of monopsony employment and substituting job security for lower salaries. Others argue that tenure reduces performance incentives making it difficult to dismiss ineffective teachers. We examine supply-side responses of teachers after the elimination of tenure before administrators could use performance to dismiss teachers. Voluntary teacher attrition increased after tenure elimination with effects concentrated in groups that are theoretically most likely to value job protections. Specifically, tenure removal increased exit of teachers with bottom decile value-added measures and retirement eligible teachers.