We anticipate that, for a large proportion of the subjects enrolled in this protocol, nonadherence, with or without drug resistance, is the most common reason for the virologic failure. Another objective for the study is to assess the impact of a 7-day, inpatient, selfguided directly observed therapy (DOT) on HIV RNA kinetics, when subjects will receive their pre-enrollment ART regimens. During the DOT period, subjects will request their antiretroviral drugs at a pre-arranged time reflecting their home medication schedule. Failure to do so will be recorded and the medications will then be provided by the nursing staff. Adherence and psychosocial assessments will also be performed. Plasma concentrations from at least one of the antiretroviral drugs in the regimen will be measured on the first and last day of DOT to determine if suboptimal drug plasma concentration was a contributing factor to virologic failure.