Three approaches were compared for improving adherence to biweekly directly observed prophylaxis for tuberculosis in the homeless: $5 biweekly money incentive (MI) for adherence to DOPT, $5 value biweekly non-money incentive (NMI) for adherence to DOPT, and $5 biweekly money incentive supplemented by a peer community outreach worker (MI + PCOW). The outreach worker assisted subjects with completion of adherence to DOPT. Predictors of adherence to DOPT were examined, including sociodemographic, psychological and behavioral, and environmental factors.