['The Spine End Results Registry (2003-2004) is a registry of prospectively collected data of all patients undergoing spinal surgery at the University of Washington Medical Center and Harborview Medical Center. Insurance data were prospectively collected and used in multivariate analysis to determine risk of perioperative complications.', 'Given the negative financial impact of surgical site infections (SSIs) and the higher overall complication rates of patients with a Medicaid payer status, we hypothesized that a Medicaid payer status would have a significantly higher SSI rate.', 'The medical literature demonstrates lesser outcomes and increased complication rates in patients who have public insurance than those who have private insurance. No one has shown that patients with a Medicaid payer status compared with Medicare and privately insured patients have a significantly increased SSI rate for spine surgery.', 'The prospectively collected Spine End Results Registry provided data for analysis. SSI was defined as treatment requiring operative debridement. Demographic, social, medical, and the surgical severity index risk factors were assessed against the exposure of payer status for the surgical procedure.', "The population included Medicare (N = 354), Medicaid (N = 334), the Veterans' Administration (N = 39), private insurers (N = 603), and self-pay (N = 42). Those patients whose insurer was Medicaid had a 2.06 odds (95% confidence interval: 1.19-3.58, P = 0.01) of having a SSI compared with the privately insured."] Is medicaid status associated with higher surgical site infection rates after spine surgery?