Organ transplantation is an expensive, life-saving technology. Previous studies have found that few transplant recipients in the United States lack health insurance (in part because patients may become eligible for special coverage because of their disability and transplant teams vigorously advocate for their patients). Few data are available on the insurance status of U.S. organ donors. The authors analyzed the 2003 National Inpatient Sample (NIS), a nationally representative 20 percent sample of U.S. hospital stays, and identified incident organ donors and recipients using ICD-9-CM diagnosis and procedure codes. The NIS sample included 1,447 organ donors and 4,962 transplant recipients, equivalent after weighting to 6,517 donors and 23,656 recipients nationwide; 16.9 percent of organ donors but only 0.8 percent of transplant recipients were uninsured. In multivariate analysis, compared with other inpatients organ donors were much more likely to be uninsured (OR 3.41, 95% CI 2.81-4.15), whereas transplant recipients were less likely to lack coverage (OR 0.08, 95% CI 0.06-0.12). Many uninsured Americans donate organs, but they rarely receive them.