There is a large gap between what physicians do for patients with chronic diseases and what should be done.1 Most physicians lack the time, information technology, and financial incentives to develop organized processes to systematically improve the quality of care provided to these patients.2 During the past decade, 2 main models have emerged to address this “quality chasm” in outpatient care: disease management and the chronic care model. Early in 2005, the Center for Medicare & Medicaid Services (CMS) will begin a large disease management initiative that may profoundly impact patient care and the organization of physician practice. But few physicians are aware of this initiative, and in general, neither disease management, nor the chronic care model are easily understood. Neither model appears in the index of a major collection of essays on medical group practice published in 2004.3 This article will describe the CMS initiative, and describe and compare the disease management and chronic care model models and the effects they may have on physician practice and on patient care.