This language isn't very helpful. It is likely paid for from general tax revenue. That might be a better implementation but it certainly isn't "free". And if it isn't explicitly paid for via tax revenue it will end up being paid for via inflation if the government spending is out of line with its revenue.

As is common in these discussions, I’ll reference the French system as I experienced it.

If you have to go to the hospital, that’s not billed to you.

If you see your GP, they charge you up front. There’s no copay as in the US system, the doctor just charges what they want. The doctor doesn’t keep any significant medicine on prem. If you need a vaccine, they write a script that you take to the pharmacy and return with. In either case, you submit your paperwork after the fact and get reimbursed. For office visits it’s 80% of the “reasonable and customary” changes. For medicine it’s usually 50-60%.

You can purchase additional insurance that covers more of these costs, but I didn’t see any value in it for my situation.

When I left, French insurance companies were setting up US style networks with doctors. If you saw an in-network provider, you were reimbursed more.

Only the truly indigent get “free” healthcare under the French system.