Many of the democratizing opportunities provided by community colleges are diminished in the eyes of policy makers by inadequate rates of success. In particular, large proportions of students who enter community colleges do not persist for longer than a semester, complete a program, or attain a credential. This review critically examines academic and policy research in search of explanations, emphasizing what is known about challenges stemming from three levels of influence: the macro-level opportunity structure; institutional practices; and the social, economic, and academic attributes students bring to college. It provides examples of how factors operating at each level affect rates of success at key times, including the initial transition to college, the experience of remedial education, and persistence through credit-bearing coursework. The article also discusses potential and ongoing reforms that could increase rates of community college success by addressing one or more areas of influence (the macro, the institutional, or the individual). It is concluded that increasing success in the open-access, public 2-year sector requires reforms directed at multiple levels and cannot be achieved with either student- or institution-focused incentives alone. (Contains 1 table and 1 note.)