The investigators will evaluate the efficacy of a comprehensive 12-week contingency management intervention for treating alcohol dependence for persons with severe mental illness who are seen within the context of a community mental health center setting. The primary contingency will be submission of alcohol-free urines. Additional reinforcers will be provided for intensive outpatient addiction treatment attendance. Reinforcers will be vouchers or actual items useful for day-to-day living. Participants will be 120 adults diagnosed with alcohol dependance and severe mental illness.