The purpose of this study is to compare voucher-based contingency management (CM) procedures to a lower-cost CM system that provides opportunities to win prizes. Cocaine-dependent outpatients are randomly assigned to (a) standard treatment, (b) standard treatment plus usual magnitude prize CM, (c) standard treatment plus higher magnitude prize CM, or (d) standard treatment plus voucher CM. Urine and breath samples are collected 2-3x/week for 14 weeks. Follow-up interviews are conducted at 1,3,6 and 9 months following intake during which substance use and psychosocial functioning are assessed.

Inclusion criteria:

• age > 18 years
• current DSM-IV diagnosis of cocaine dependence
• received methadone treatment at the clinic for at least 3 months
• on a stable dose of methadone (no changes in dosing) for at least one month and not presently requesting a dose alteration
• submitted one or more clinic-collected cocaine positive urine samples in the previous 3 months
• English speaking
• pass a brief quiz related to understanding of the informed consent form

Exclusion criteria:

• have a serious, uncontrolled psychiatric illness (e.g., acute schizophrenia, bipolar disorder, severe or psychotic major depression, or suicide risk)
• have dementia (<23 on the Mini Mental State Exam; Folstein et al. 1975)
• are in recovery from pathological gambling