In this issue of JAMA Internal Medicine, Rivera-Hernandez and colleagues1 report that Medicare Advantage (MA) enrollees in the territory of Puerto Rico receive substantially lower quality of care than white or Hispanic enrollees residing in the United States (50 states and Washington, DC). The authors found that these disparities persisted after adjusting for age, sex, and poverty. For example, compared with Hispanic MA enrollees residing in the United States, MA enrollees residing in Puerto Rico showed worse care in 10 of the 17 measures of quality of care examined. In several cases the differences were large: MA beneficiaries in Puerto Rico “had rates of disease-modifying antirheumatic drug therapy, systemic corticosteroid treatment, and bronchodilator therapy that were 21.3 to 23.8 percentage points lower than those of Hispanic enrollees in the United States.”1