BACKGROUND: Research demonstrates that the patientcentered medical home (PCMH) is associated with improved clinical outcomes and quality of care, and the populations that can most benefit from this model require long-term management, e.g., persons with chronic illness and behavioral health conditions. However, different populations may not benefit equally from the PCMH, and empirical evidence about the effects of this model on racial disparities is limited. OBJECTIVE: Estimate the association between enrollment in National Committee for Quality Assurance (NCQA)-recognized PCMHs and racial disparities in quality of care for adults with major depressive disorder (MDD) and comorbid medical conditions. DESIGN: Applying a quasi-experimental instrumental variable design to account for differential selection into the PCMH, we used generalized estimating equations to determine the probability of receiving eight diseasespecific quality measures. SUBJECTS: Medicaid enrollees in three states not dually enrolled in Medicare, ages 18-64 with MDD and > 1 other chronic condition. A subgroup analysis was conducted for enrollees with comorbid diabetes. INTERVENTIONS: Enrollment in an NCQA-recognized PCMH. MAIN MEASURES: Disease-specific quality indicators for MDD (e.g., antidepressant use, receipt of psychotherapy), and for diabetes, (e.g. A1c testing, LDL-C testing, retinal exams, and medical attention for nephropathy). KEY RESULTS: PCMH enrollment was associated with an increase in the overall likelihood of receiving six of eight recommended services and a decrease in the likelihood of receiving any psychotherapy (4.94 percentage points, p < 0.01) and retinal exams (5.51 percentage points, p < 0.05). Although both groups improved, PCMH enrollment was associated with an exacerbation of the Blackwhite disparity in adequate antidepressant use by 4.20 percentage points (p < 0.01). CONCLUSIONS: While PCMH enrollment may improve the overall quality of care, the effect is inconsistent across racial groups and not always associated with reductions in racial disparities in quality.