Recent studies of charter school effectiveness have questioned whether charter school networks can produce a lasting impact on students' long-term outcomes. Our study is the first to examine this issue at the network of Knowledge is Power Program (KIPP) schools, which primarily serve disadvantaged students of color and constitute the nation's largest charter school network. Using admission lotteries as a random assignment instrument, we estimate the impacts of 13 KIPP middle schools on college enrollment and persistence in college over the first two postsecondary years. Building on prior studies of KIPP that show KIPP middle schools have strong positive effects on middle school achievement, we find that KIPP middle schools also positively affect rates of enrollment in 4-year college programs. The magnitude of the estimated impact of a middle school admission offer (6.9%) and enrollment at a KIPP school (12.9%) is substantial relative to nationwide disparities in college enrollment across racial groups.