Patients with End Stage Renal Disease (ESRD) constitute a high-cost, high-need population that can greatly benefit from targeted policy initiatives to improve care coordination. In 2010, patients with ESRD made up 1.3% of the Medicare population, but accounted for 7.5% of total Medicare spending, amounting to over $20 billion.1 Adoption of the accountable care organization (ACO) model for ESRD has the potential to improve care coordination and patient outcomes. Due to complex health needs, patients in this population can require visits to multiple providers with multiple care plans. By bringing these providers together under the same organizational structure, accountable care provides the opportunity to improve quality through coordination. Though just over 1 million ESRD beneficiaries participated in the Pioneer ACO program, to date no direct studies have examined the effect of ACOs on management of ESRD.