Feldman CH, et al. - Systemic lupus erythematosus (SLE) patients (n=10,268) from 28 states in the US who registered in Medicaid (2000–2010) and in whom hydroxychloroquine (HCQ) treatment was newly received, were recruited by the experts in order to determine the effect of contextual factors, including racial composition, socioeconomic status, and the concentration of health care resources, on adherence to HCQ among SLE patients enrolled in Medicaid. Out of 10,268 SLE individuals, 15% stuck to treatment. Among patients who resided in zip code areas, lower odds of adherence with a greater percentage of black individuals was observed. Even after controlling for area-level educational attainment, percent below the federal poverty level (FPL), urbanicity, and health care resources, this correlation continued. No, statistically significant associations, could be seen with zip code–level percent Hispanic, percent white, education, or percent below FPL. In counties with more hospitals, adherence odds were higher. Hence, marked impacts of racial composition and hospital concentration on HCQ adherence were recognized among Medicaid beneficiaries with SLE. Further, to diminish high rates of nonadherence in the vulnerable populations, interventions that recognize and discuss contextual factors should be acknowledged.