Alcohol and other drug abuse (AOD) treatment is a major means of HIV/AIDS prevention, yet clients of street outreach programs (SOP) who are injection drug users (IDU), and outreach workers and staff as well, report various obstacles to enrolling clients in AOD programs. This study assessed the barriers to AOD enrollment facing high risk street outreach clients and obtained suggestions for reducing them. Data were obtained from semistructured field interviews with: 1) IDU outreach clients (N = 144) of the six SOPs in New York City (NYC) and northern suburbs supported by the Office of Alcoholism and Substance Abuse Services (OASAS), the single state agency in New York State for AOD prevention and treatment, 2) outreach workers and staff of the six SOPs (N = 55), 3) staff of detox and AOD treatment programs in major modalities treating IDUs (N = 71), and 4) officials and administrators (N = 11) in OASAS, the AIDS Institute of the Department of Health (addresses all aspects of the HIV/AIDS epidemic in New York State), and the agency for public assistance in New York City, the Human Resources Administration (HRA). Principal barriers for street outreach clients included personal-family issues, lack of insurance/Medicaid, ignorance, suspicion, and/or aversion to AOD treatment (methadone maintenance especially), "hassles" with Medicaid, lack of personal ID, lack of "slots," limited access to intake, homelessness, childcare-child custody issues. Further, about 18% had no desire for AOD services, reported no barriers, or were too enmeshed in addiction to enroll. Outreach staff cited prospective client's lack of ID and lack of Medicaid, lack of "slots," and stakeholder agency bureaucracy. Treatment staff cited lack of client readiness, "hassles" posed by welfare reform, AOD programs' own "red tape," waiting lists, and near exclusionary preference for the Medicaid-eligible. Finally, agency managers cited client factors, inadequate funding and lack of appropriate programs, treatment program requirements, and societal stigmatization of addicts. Proposed remedies included dropping ID and insurance requirements for admission, major increases in resources, funding the transporting of outreach client treatment candidates to AOD services sites, education and training initiatives, increased inter-agency cooperation, and the need for stakeholder agencies, OASAS especially, to more effectively integrate abstinence-oriented AOD services with harm reduction and the public health aspects of AOD problems.