 Optimal benefit from antiretroviral therapy ART is contingent upon consistent engagement in HIV care and reliable medication adherence. HIV-infected intravenous drug users IDUs delay entrance into and under-utilize medical care. Those who access HIV care are frequently lost to follow up or are intermittent users. Out-of-care IDUs are more likely to develop AIDS, have reduced survival, engage in risky behavior and place others at risk for HIV transmission; therefore, evidence-based tools to promote engagement of IDUs in care are urgently needed. 