Single-payer universal healthcare is, as far as I know, never based on citizenship, but rather on residency. More pragmatically, it's based on where you pay you

Single-payer universal healthcare is, as far as I know, never based on citizenship, but rather on residency. More pragmatically, it's based on where you pay your taxes. Example: I'm covered in Japan where I live and work, although I'm not a Japanese citizen. And the other way around: I'm a French citizen, but I'm not entitled to any coverage in France since I don't live/work/pay taxes there. So you probably meant non-residents and illegal immigrants. I'm not aware of non-residents (tourists, mostly) being covered anywhere. As for illegal immigrants, it depends: France has at least some free coverage, so has Spain and I'm sure some other countries. In France it's called the AME (Aide Médicale d'État). Like any system it's being gamed and abused, hence why it's being reformed and should not be copied as-is. But at 1 billion EUR/year the benefits certainly outweigh the cost.