ABSTRACT: There is little objective evidence to support concerns that patients are transferred between hospitals based on insurance status.To examine the relationship between patients' insurance coverage and interhospital transfer.Data analyzed from the 2010 Nationwide Inpatient Sample.All patients aged 18 to 64 years discharged alive from U.S. acute care hospitals with 1 of 5 common diagnoses (biliary tract disease, chest pain, pneumonia, septicemia, and skin or subcutaneous infection).For each diagnosis, the proportion of hospitalized patients who were transferred to another acute care hospital based on insurance coverage (private, Medicare, Medicaid, or uninsured) was compared. Logistic regression was used to estimate the odds of transfer for uninsured patients (reference category, privately insured) while patient- and hospital-level factors were adjusted for. All analyses incorporated sampling and poststratification weights.Among 315 748 patients discharged from 1051 hospitals with any of the 5 diagnoses, the percentage of patients transferred to another acute care hospital varied from 1.3% (skin infection) to 5.1% (septicemia). In unadjusted analyses, uninsured patients were significantly less likely to be transferred for 3 diagnoses (P 0.05). In adjusted analyses, uninsured patients were significantly less likely to be transferred than privately insured patients for 4 diagnoses: biliary tract disease (odds ratio, 0.73 [95% CI, 0.55 to 0.96]), chest pain (odds ratio, 0.63 [CI, 0.44 to 0.89]), septicemia (odds ratio, 0.76 [CI, 0.64 to 0.91]), and skin infections (odds ratio, 0.64 [CI, 0.46 to 0.89]). Women were significantly less likely to be transferred than men for all diagnoses.This analysis relied on administrative data and lacked clinical detail.Uninsured patients (and women) were significantly less likely to undergo interhospital transfer. Differences in transfer rates may contribute to health care disparities.National Institutes of Health.