<P> In the United States, Medicare is a national health insurance program, now administered by the Centers for Medicaid and Medicare Services of the U.S. federal government but begun in 1966 under the Social Security Administration . United States Medicare is funded by a combination of a payroll tax, premiums and surtaxes from beneficiaries, and general revenue . It provides health insurance for Americans aged 65 and older who have worked and paid into the system through the payroll tax . It also provides health insurance to younger people with some disability status as determined by the Social Security Administration, as well as people with end stage renal disease and amyotrophic lateral sclerosis . </P> <P> In 2015, Medicare provided health insurance for over 55 million--46 million people age 65 and older and 9 million younger people . On average, Medicare covers about half of the healthcare charges for those enrolled . The enrollees must then cover their remaining costs either with supplemental insurance, separate insurance, or out of pocket . Out - of - pocket costs can vary depending on the amount of healthcare a Medicare enrollee needs . These out - of - pocket costs might include deductibles and co-pays; the costs of uncovered services--such as for long - term, dental, hearing, and vision care--and supplemental insurance premiums . </P>

What tax is used to provide medical services for persons over the age of 65