DEPARTMENT OF HEALTH AND HUMAN SERVICES  
"THE DEPARTMENT OF HEALTH AND HUMAN SERVICES is the United States government's principal agency for protecting the health of all Americans and providing essential human services, especially for those who are least able to help themselves."

"THE DEPARTMENT INCLUDES MORE THAN 300 PROGRAMS, covering a wide spectrum of activities. Some highlights include:

Medical and social science research
Preventing outbreak of infectious disease, including immunization services
Assuring food and drug safety
Medicare (health insurance for elderly and disabled Americans) and Medicaid (health insurance for low-income people)
Financial assistance and services for low-income families
Improving maternal and infant health
Head Start (pre-school education and services)
Preventing child abuse and domestic violence
Substance abuse treatment and prevention
Services for older Americans, including home-delivered meals
Comprehensive health services for Native Americans
HHS IS THE LARGEST GRANT-MAKING AGENCY in the federal government, providing some 60,000 grants per year. HHS' Medicare program is the nation's largest health insurer, handling more than 900 million claims per year.

HHS WORKS CLOSELY WITH STATE, LOCAL AND TRIBAL GOVERNMENTS, and many HHS-funded services are provided at the local level by state, county or tribal agencies, or through private sector grantees. The Department's programs are administered by 11 HHS operating divisions, including eight agencies in the U.S. Public Health Service and three human services agencies. In addition to the services they deliver, the HHS programs provide for equitable treatment of beneficiaries nationwide, and they enable the collection of national health and other data."

http://www.hhs.gov