This study, supported by the National Institutes of Health and the National Institute on Minority Health and Health Disparities, is evaluating changes in access to care, clinical processes of care, and clinical outcomes among Medicare beneficiaries with end-stage renal disease (ESRD). Its purpose is to determine how health disparity populations were affected by the recent Medicare ESRD payment reform implemented January 1, 2011. This study uses the Medicare end-stage renal payment reform as a natural experiment to study whether changes in financing for dialysis services affects clinical practices in ways that could reduce or widen health disparities, leading to improved or worsened health outcomes.