Section 721 of the Medicare Modernization Act of 2003 (MMA) authorized development and testing of voluntary chronic care improvement programs, now called Medicare Health Support, to improve the quality of care and life for people living with multiple chronic illnesses. Chronic conditions are a leading cause of illness, disability, and death among Medicare beneficiaries and account for a disproportionate share of health care expenditures. About 14 percent of Medicare beneficiaries have heart failure, but they account for 43 percent of Medicare spending. About 18 percent of Medicare beneficiaries have diabetes, yet they account for 32 percent of Medicare spending. The initiative assessed whether the benefits of better managing and coordinating the care of these beneficiaries would result in reduced health risks, an improved quality of life, and savings to the Medicare program and the beneficiaries. The programs were overseen by the Centers of Medicare and Medicaid Services (CMS) and operated by health care organizations chosen through a competitive selection process. Phase I program operations began between August 2005 and January 2006. Phase I ended on August 31, 2008 and CMS is assessing the results of this program.