States regulate entry into principalships, including requirements for prior experience as a teacher or assistant principal, to guard against poor school leadership and bad outcomes for students. Such requirements might be expected to reduce the variation in principal quality and achievement growth by excluding applicants in the lower tail of the effectiveness distribution, but differences in state standardized tests, family circumstances, state economic conditions, and myriad state and local policies and conditions prevent direct analyses of their effects on principal quality. To learn more about their likely impacts, we describe pathways to the principalship in terms of prior teaching experience, and assistant principal and principal experience, across six states with substantial differences in context, regulations, and student populations. There are sizeable differences across states in the shares of principals without prior experiences as a teacher or assistant principal but only modest differences in estimates of the variance of principal effectiveness, which suggests that prior experience requirements create barriers to becoming a principal and do not succeed in raising the principal effectiveness floor. Schools serving more economically disadvantaged students and Black students are more likely to have principals without prior experience as a teacher, but the findings suggest that stricter prior experience requirements may not benefit—or could potentially even harm—students in schools that have more difficulty attracting and retaining principals.