Debates about developmental instruction have prompted postsecondary institutions to justify their developmental courses. This study investigated a method of documenting the benefits of developmental courses that involves using placement test scores to predict college outcomes separately for students who take a developmental course before taking standard courses and for those who enroll in standard courses directly. College outcomes were defined in terms of success in standard courses or retention in college. If, among students with a given placement test score, the predicted probability of success or of retention is higher for students who took a developmental course, one would have evidence that this developmental course is beneficial. Multi-year data from two large Midwestern universities were used to illustrate this approach. Simply taking a developmental course did not usually result in benefits. Students who earned high grades (at least a B) in developmental courses, however, were more likely than other students to succeed in standard courses or to persist in college. (Contains 6 figures.)