OBJECTIVES: Medication adherence is a major obstacle to overcome when treating chronic medical conditions. Many factors can influence how well a medication regimen is complied with, including patient demographics such as race. The aim of this study was to determine how race can affect medication adherence in Medicaid-enrolled patients with chronic disease. METHODS: We examined the association between race and controller medication adherence in confounder adjusted multivariate analyses on data from 3 retrospective cohorts enrolled in the North Carolina Medicaid program. These cohorts included patients with primary diagnoses of asthma (n=710), type 2 diabetes (n=2655), and psoriasis (n=186). The data for these studies was extrapolated from the North Carolina Medicaid claims and eligibility files and patients were followed up for a minimum of two years. RESULTS: The results were mixed across disease states. In patients with type 2 we found that medication adherence rates (using medication possession ratios) for oral antidiabetics was significantly higher for whites [59%] as compared to African Americans [54%] (p<0.05). Similarly, in patients with asthma, we found that African American patients were 65% less likely to have the recommended medication possession rate of at least 80% [RR: 0.35 , 95% CI: 0.15-0.81]. There were no significant patient differentials in controller medication adherence by race in patients with psoriasis. CONCLUSION: The results were mixed across disease states. In patients with type 2 we found that medication adherence rates (using medication possession ratios) for oral antidiabetics was significantly higher for whites [59%] as compared to African Americans [54%] (p<0.05). Similarly, in patients with asthma, we found that African American patients were 65% less likely to have the recommended medication possession rate of at least 80% [RR: 0.35 , 95% CI: 0.15-0.81]. There were no significant patient differentials in controller medication adherence by race in patients with psoriasis.