After stratification, sites were assigned randomly to the three programs; the homeless participants were then recruited into the program associated with their site. Participants recruited from outdoor locations were entered systematically into each of the three programs as they were enrolled. All sites were within 5 miles of the Weingart Center, where the study was conducted. Recruitment procedures consisted of posting flyers in the approved sites to inform residents of the study and to provide information for interested homeless persons who wanted to contact study staff. Detailed information was provided to homeless residents at the shelter and rehabilitation sites and to homeless street persons who came into the Weingart Center during scheduled clinic visits. After obtaining written informed consent to screening, outreach workers administered a brief questionnaire covering basic sociodemographic characteristics and a hepatitis-related health history designed to assess eligibility for the study. Eligible and interested participants then completed a second written informed consent followed by pretest counseling and a blood draw for HAV, HBV, HCV, and HIV assays.