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, post-matching 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.