ABSTRACT: BACKGROUND:Millions of Americans live in the US territories, but health outcomes and payments among Medicare beneficiaries in these territories are not well characterized. METHODS:Among Fee-for-Service Medicare beneficiaries aged 65 years and older hospitalized between 1999 and 2012 for acute myocardial infarction (AMI), heart failure (HF), and pneumonia, we compared hospitalization rates, patient outcomes, and inpatient payments in the territories and states. RESULTS:Over 14 years, there were 4,350,813 unique beneficiaries in the territories and 402,902,615 in the states. Hospitalization rates for AMI, HF, and pneumonia declined overall and did not differ significantly. However, 30-day mortality rates were higher in the territories for all 3 conditions: in the most recent time period (2008-2012), the adjusted odds of 30-day mortality were 1.34 [95% confidence interval (CI), 1.21-1.48], 1.24 (95% CI, 1.12-1.37), and 1.85 (95% CI, 1.71-2.00) for AMI, HF, and pneumonia, respectively; adjusted odds of 1-year mortality were also higher. In the most recent study period, inflation-adjusted Medicare in-patient payments, in 2012 dollars, were lower in the territories than the states, at $9234 less (61% lower than states), $4479 less (50% lower), and $4403 less (39% lower) for AMI, HF, and pneumonia hospitalizations, respectively (P<0.001 for all). CONCLUSIONS AND RELEVANCE:Among Medicare Fee-for-Service beneficiaries, in 2008-2012 mortality rates were higher, or not significantly different, and hospital reimbursements were lower for patients hospitalized with AMI, HF, and pneumonia in the territories. Improvement of health care and policies in the territories is critical to ensure health equity for all Americans.