This article employs event history analysis to explore the factors that were associated with the rapid uptake of teacher evaluation reform. We investigate three hypotheses for this rapid adoption: (a) downward diffusion from the federal government through Race to the Top (RTTT), (b) upward diffusion from large school district policies, and (c) the influence of intermediary organizations. Although RTTT clearly played a role in state adoption, our analysis suggests that having a large district implement teacher evaluation reform is the most consistent predictor of state adoption. Intermediary organizations appeared to play a role in the process as well.