This is a Phase III, community-level, randomized controlled study, in which 48 communities (10 in Tanzania, 8 in Zimbabwe, 8 in South Africa-Soweto, 8 in South Africa-Vulindlela, and 14 in Thailand) were randomized to receive either a community-based HIV voluntary counseling and testing (CBVCT) intervention or standard clinic-based VCT (SVCT). The CBVCT intervention has three major strategies: (1) to make VCT more available in community settings; (2) to engage the community through outreach; and (3) to provide post-test support. These three strategies are designed to change community norms and reduce risk for HIV infection among all community members, irrespective of whether they participated directly in the intervention. The primary objective (Aim 1) of this study is to test the hypothesis that communities receiving 2-1/2 years of CBVCT, relative to communities receiving 2-1/2 years of SVCT, will have significantly lower prevalence of recent HIV infection. The secondary objective (Aim 2) is to test the hypotheses that CBVCT communities, relative to SVCT communities, will at the end of the intervention period report significantly: less HIV risk behavior, higher rates of HIV testing, more favorable social norms regarding HIV testing, more frequent discussions about HIV, more frequent disclosure of HIV status, less HIV-related stigma, and fewer HIV- related negative life events. Aim 3 of the study will be to assess whether CBVCT is cost-effective compared to SVCT. A random sample of persons aged 16 to 32 from each study community was selected at baseline, and will be selected post intervention, for measuring primary and secondary endpoints. Aim 1 will be evaluated by comparing the post-intervention prevalence of recent HIV infection in CBVCT and SVCT communities, using an algorithmic approach comprised of CD4+ T-cell counts, the HIV-1 BED Incidence EIA (Calypte), Avidity Index (BioRad), and HPLC for ART residues (HPTN Core Lab/JHU). Aim 2 will be evaluated by comparing a variety of behavioral measures at baseline and post intervention. Aim 3 will be evaluated in terms of cost per HIV infection averted and disability-adjusted life years (DALYs) saved.