Phosphatidylethanol (PEth) is a direct biomarker of alcohol that can detect moderate to heavy drinking with high sensitivity and specificity over 3-week periods. Reinforcing negative PEth results alongside attendance may increase the proportion of participants who respond to CM during and post treatment. In the proposed study, the investigators will collect PEth samples every 3 weeks for 12 weeks in 150 participants initiating outpatient treatment for alcohol use disorders. Using a two-group randomized design, participants will be assigned to standard care with PEth monitoring alone or with CM for attending treatment and submitting PEth negative samples. Compared to standard care and monitoring, the investigators expect that the CM intervention will result in greater attendance, more PEth negative samples, and higher proportions of self-reported non-drinking days, along with lower proportions of heavy drinking days, over the short term and the long term, measured throughout a 12-month follow-up. The investigators anticipate that the reinforcement intervention may decrease other drug use and sexual risk behaviors that spread HIV, reduce psychiatric symptoms, and improve quality of life as well.

Inclusion Criteria:

• in intensive outpatient treatment
• DSM-5 diagnosis of an alcohol use disorder

Exclusion Criteria:

• have a condition that may hinder study participation