According to the Department of Health and Human Services (HHS), Medicare is a health insurance program while Medicaid is an assistance program. Medicare is funded by a trust that covers the costs of the program.  Eligible enrollees must either be over 65 years old, must be disabled, or must require dialysis treatment. Medicaid defers health care costs for low-income people of all ages.  It is jointly run by Federal and State governments and therefore varies from state to state.