A sizeable body of evidence has documented the effectiveness of Teach For America (TFA) corps members at raising the mathematics test scores of their students, though little is known about the program's impact at the school level. TFA's recent placement strategy in the Miami-Dade County Public Schools, in which large numbers of TFA corps members are placed as clusters into a targeted set of disadvantaged schools, provides an opportunity to evaluate the impact of the TFA program on broader school performance. This study examines whether the influx of TFA corps members led to a spillover effect on other teachers' performance. We find that many of the schools chosen to participate in the cluster strategy experienced large subsequent gains in mathematics achievement. These gains were driven in part by the composition effect of having larger numbers of effective TFA corps members. However, we do not find any evidence that the clustering strategy led to any spillover effect on schoolwide performance. In other words, our estimates suggest that the extra student gains for TFA corps members under the clustering strategy would be equivalent to gains resulting from an alternate placement strategy in which corps members were evenly distributed across schools.