This chapter discusses the role of disease prevention and health promotion in a comprehensive health care system. Social scientists use the several models to describe different approaches to health care in the United States the medical model, the social model, and the health promotion model. The medical model dominates Medicare health benefit expenditures. Inpatient hospital services and physician payments make up 34 percent of Medicare payments. The social model of health care aims to keep older people in the community. Disease prevention and health promotion include things the medical care take for granted, such as water and air quality standards, vaccinations, and regular medical checkups. Physician fees, costly intensive daily hospital service, administration costs in hospitals, the use of high technology, and high insurance administration costs all add to the high cost of US health care. Medicare and Medicaid cover some health care costs.