Antiretroviral therapy (ART) has significantly decreased the morbidity and mortality of HIV infection. However, adherence challenges in taking daily oral ART persist. A retrospective cohort study across 31 countries from 2010-19 reported that only 65% of people with HIV (PWH) on ART exhibited virologic suppression (VS) three years after starting ART;1 the rate of VS in South Africa among PWH on ART is 60-65%. Adherence barriers span individual and structural factors, such as stigma, recall difficulties, housing and/or food insecurity, mental illness, substance use, transportation, stock-outs, and other factors that vary by country and population. Adherence interventions can benefit from direct objective adherence monitoring. Pharmacologic metrics of adherence assess drug levels in plasma, dried blood spots, hair (a metric our group pioneered) or urine and predict outcomes more accurately than self-reported adherence. However, most of these metrics preclude real-time assessment, requiring expensive laboratory equipment and trained laboratory personnel. Thus, few adherence interventions have successfully incorporated objective metrics, likely due to laboratory and shipping delays. A low-cost (\<$2/test) point-of-care adherence metric - developed by our group - should allow for real-time biofeedback and improve the impact of metric-driven adherence interventions.