Alcohol addiction is as a chronic relapsing disorder. High magnitude and long-duration voucher-based abstinence reinforcement is one of the most effective treatments for alcohol and drug addiction and can maintain abstinence over extended periods of time, but practical methods of implementing these interventions are needed. Workplaces could be ideal and practical vehicles for arranging and maintaining abstinence reinforcement over long time periods. Our research on a model Therapeutic Workplace has shown that employment-based abstinence reinforcement, in which participants must provide alcohol- or drug-free urine samples to maintain maximum pay, can maintain alcohol and drug abstinence. Now we need to develop effective and economically sound methods to arrange long-term exposure to employment-based abstinence reinforcement. We are proposing to evaluate the effectiveness and economic benefits of a Wage Supplement Model of arranging long-term exposure to employment-based abstinence reinforcement. Under this model, successful Therapeutic Workplace participants are offered abstinence-contingent wage supplements if they obtain and maintain competitive employment. Governments have used wage supplements effectively to increase employment in welfare recipients. The Wage Supplement Model harnesses the power of wage supplements to promote employment, while simultaneously using the wage supplements to reinforce alcohol abstinence. The intervention will combine 3 elements -- the Therapeutic Workplace, Individual Placement and Support (IPS) supported employment, and abstinence-contingent wage supplements. IPS is a supported employment intervention that has been proven effective in promoting employment in adults with severe mental illness. Under this model, participants will be exposed to the Therapeutic Workplace to initiate alcohol abstinence and establish job skills. To promote employment and prevent relapse to alcohol use, participants will receive IPS Plus Abstinence-Contingent Wage Supplements. A randomized trial will evaluate the effectiveness and economic benefits of the Abstinence-Contingent Wage Supplement Model in promoting employment and sustaining alcohol abstinence in homeless adults with alcohol use disorder (N=130). Participants will be enrolled in the Therapeutic Workplace for 3 months and then randomly assigned to a Usual Care Control group or an IPS Plus Abstinence-Contingent Wage Supplement group for one year. Usual Care Control participants will be offered counseling and referrals to employment and treatment programs. IPS Plus Abstinence-Contingent Wage Supplement participants will receive the IPS intervention and abstinence- contingent wage supplements. Throughout the study, a wearable alcohol biosensor will be used to continuously monitor alcohol use. This novel intervention could be an effective and economically sound way to promote long-term alcohol abstinence and employment in homeless adults with alcohol use disorder, a population at risk for many adverse outcomes because of their poverty, unemployment, homelessness and alcohol use.