Contingency management (CM) is effective in enhancing retention in therapy. After an 8-week baseline, four community-based substance abuse treatment clinics were exposed in random order to 16 weeks of standard care with CM followed by 16 weeks of standard care without CM or vice versa. In total, 75 outpatients participated. Patients who were enrolled in the clinics when the CM treatment phase was in effect attended a significantly greater percentage of therapy sessions than patients who were enrolled in treatment when CM was not in effect. This study is one of the first to investigate CM in community settings implemented entirely by community clinicians, and results suggest that CM is effective in improving therapy attendance. (Contains 1 table and 2 figures.)