Medicare (United States)
Medicare is a social insurance
Social insurance
Social insurance is any government-sponsored program with the following four characteristics:* the benefits, eligibility requirements and other aspects of the program are defined by statute;...

 program administered by the United States government, providing health insurance
Health insurance
Health insurance is insurance against the risk of incurring medical expenses among individuals. By estimating the overall risk of health care expenses among a targeted group, an insurer can develop a routine finance structure, such as a monthly premium or payroll tax, to ensure that money is...

 coverage to people who are aged 65 and over; to those who are under 65 and are permanently physically disabled or who have a congenital physical disability; or to those who meet other special criteria. Medicare in the United States somewhat resembles a single-payer health care
Single-payer health care
Single-payer health care is medical care funded from a single insurance pool, run by the state. Under a single-payer system, universal health care for an entire population can be financed from a pool to which many parties employees, employers, and the state have contributed...

 system, but is not. Before Medicare, only 51% of people aged 65 and older had health care coverage, and nearly 30% lived below the federal poverty level.