BACKGROUND: Disparities based on insurance status in the American health care system are well established. However, to the authors' knowledge, this is the first study to evaluate variables that may explain differences based on payer type in the outcomes after surgery for spinal metastases. METHODS: Data from the Nationwide Inpatient Sample (2005)(2006)(2007)(2008) were retrospectively extracted. Patients ages 18 to 64 years who underwent surgery for spinal metastases were included. Multivariate logistic regression was performed to calculate the adjusted odds of in-hospital death and the development of a complication for Medicaid recipients and for those without insurance compared with privately insured patients. All analyses were adjusted for differences in patient age, gender, primary tumor histology, socioeconomic status, hospital bed size, and hospital teaching status. RESULTS: A total of 2157 hospital admissions were evaluated. The adjusted odds of in-hospital death were significantly higher for Medicaid recipients (crude rate: 6.5%; odds ratio [OR]