Developmental education has been cited as one of the most difficult issues facing community colleges. Despite the controversy and changes to educational policy regarding developmental education, there is a notable dearth of rigorous research measuring the causal effect of remediation on community college student outcomes. The present study uses data from the Beginning Postsecondary Students Longitudinal Study (BPS: 04/09) to measure the impact of developmental education on community college students' odds of persistence and vertical transfer after controlling for enrollment in remediation and institutional-level variables. Propensity score matching results reveal that students who enroll in developmental courses are systematically different from community college students who do not remediate in gender, ethnicity, first-generation status, academic preparation and experiences during high school, and delayed college entry. Moreover, postmatching hierarchical generalized linear modeling (HGLM) findings demonstrate that developmental education may overall serve to decrease community college students' odds of successfully transferring to a 4-year institution, with negative impacts on students enrolled in English and mathematics courses. Implications for research, policy, and practice are addressed.