The way I think about it is that in countries where there is socialized medicine, they tax citizens 50% or more of their income to pay for it. They also must go to the doctor their socialized medecine sends them to. We here in the US can choose who we want to go to if we pay cash, or we go choose the health plan we want to buy and go to the doctors in that plan.
At 65, we in the US have medicare health coverage which is a government run program. Since we pay into social security out of our income and it's deducted out of each pay check by a small percentage, finally at 65 we start getting it back with Medicare health insurance and Social Security benefits.

also to add~ if someone is disabled before they reach 65, they can apply for Medicaid and Social Security Disability benefits.