Medicare beneficiaries' medical needs, and where beneficiaries undergo treatment, have changed dramatically over the past two decades. Twenty years ago, most spending growth was linked to intensive inpatient (hospital) services, chiefly for heart disease. Recently, much of the growth has been attributable to chronic conditions such as diabetes, arthritis, hypertension, and kidney disease. These conditions are chiefly treated not in hospitals but in outpatient settings and by patients at home with prescription drugs. Health reform must address changed health needs through evidence-based community prevention, care coordination, and support for patient self-management.