The even better thing now is that with the "No Surprises Act" taking effect, I could presumably walk into any hospital in the US and never get billed more than

The even better thing now is that with the "No Surprises Act" taking effect, I could presumably walk into any hospital in the US and never get billed more than I'd have to pay with Kaiser. If you're in an area where Kaiser's hospitals are, non-Kaiser hospitals will generally work with Kaiser. It's not like you get to choose which one you go to in an emergency. Outside of the states that Kaiser is in, you're usually fine but there are many horror stories about hospitals asking for fees beyond what Kaiser will cover under their global ER coverage.