Individuals who have a drunk driving arrest and are at risk for ongoing heavy drinking will be recruited to test the efficacy of contingency management for reducing alcohol use and identifying mechanisms of change. We will recruit those arrested for drunk driving offenses, ≥ 21 years of age, who at risk for ongoing heavy alcohol use and randomize them to one of two groups: control or a contingency management. Participants experience 8 weekly assessments of current alcohol use and other variables associated with changes in alcohol use. Post-intervention, participants will return to the laboratory once per month at 3, 6, 9, and 12 months post-study entry for follow-up procedures to determine the mechanisms of drinking behavior change.