Knowing at antiretroviral therapy (ART) initiation which patients might be at greatest risk for failure to achieve viral suppression would enable providers to target patients most in need and tailor their care appropriately. This study involved multilevel modeling of data from a randomized controlled trial among outpatients in Seattle, WA, USA. The 224 participants initiating or switching ART at baseline were 24% female, 34% heterosexual, and 47% Caucasian. Of 24 baseline demographic and psychosocial patient-level variables modeled in separate generalized estimating equations, only employment predicted changes in HIV-1 RNA viral load or CD4 lymphocyte count over the course of the 9-month trial. Although the findings require replication, they suggest adherence support strategies should emphasize close monitoring and support for all patients initiating ART.