A federal program for the elderly and disabled, regardless of financial status. It is not necessary, as with Medicaid, for Medicare recipients to be poor. A U.S. health insurance program for people aged 65 and over, for persons eligible for social security disability payments for two years or longer, and for certain workers and their dependents who need kidney transplantation or dialysis. Monies from payroll taxes and premiums from beneficiaries are deposited in special trust funds for use in meeting the expenses incurred by the insured. It consists of two separate but coordinated programs: hospital insurance (Part A) and supplementary medical insurance (Part B). Medicare covers more than 34 million Americans (16% of population) at an annual estimated cost of more than $133 billion.