Also, some people get both, depending on if their ss is low enough, and rest of income/resources is not over allowable limit. SSI (needs based program) you get Medicaid (free). SSD disabled after 24 months get Medicare, or age 65 Medicare. This is short version summary, of eligibility (not all inclusive criteria, mileage varies depending on exceptions to the rules, i.e. widows benefits, certain conditions for disability like end stage renal disease, etc.). I'll shush it up now! This is what I do for a living, so hard not to speak to it (ad nauseam).