A task-based behavioral contingency-the "treatment reinforcement plan" (TRP)-was implemented with cocaine-using methadone patients to increase treatment engagement and retention. Subjects (N = 57) were rewarded up to $15 per week in travel/food/entertainment vouchers for the completion of tasks related to their individual treatment needs. Eighteen types of tasks were contracted and completed with varying frequency. The largest categories of tasks were related to therapy attendance (N = 272; 58% completed), obtaining public entitlements (N = 165; 61% completed), medical/psychiatric appointments (N = 155; 70% completed), and obtaining Medicaid (N = 96; 54% completed). The highest proportion of tasks completed were related to human immunodeficiency virus (HIV) testing/education (N = 19; 100% completed), managing money (N = 17, 94% completed), and legal matters (N = 16, 88% completed). Successful TRP involvement during months 1-2 predicted longer retention in methadone treatment, greater therapy attendance during months 3-6, and lower proportion of cocaine-positive urines at 6-month follow-up. This research supports recent findings that early treatment engagement is associated with improved therapeutic relationships, increased retention, and reduced cocaine use. Behavioral counseling techniques may be especially helpful in addressing the complex needs of high-risk methadone patients, which in turn may facilitate treatment process and positive outcomes.