Medicare was created to help older Americans and certain disabled individuals pay their medical bills, and the program is paid for by the Social Security contributions you make while working. Most people age 65 or older are eligible for coverage based on their work history or that of their spouse.
Medicaid differs from Medicare in a couple key ways. First, Medicaid is available to low-income Americans, regardless of age. Second, Medicaid is largely handled by the states, while Medicare is administered by the federal government.