The second phase of the study will examine the contingency management procedure applications. Each of the three contingency management procedure applications targets specific behaviors that, when reinforced, may interact with carbidopa/levodopa to produce clinical benefits. Participants will receive relapse prevention therapy combined with a contingency management procedure that targets clinic attendance, medication compliance, and cocaine abstinence. Study visits will occur weekly throughout the study. In addition, participants will complete a one-year follow-up visit.