I believe I'm correct when I say that there are not protections from incurring excessive out of network fees that insurance won't pay even if you're covered.
As in, you go to the hospital but the doctors that work your case aren't part of your insurance network, so you're given a bill that you're responsible for and your insurance won't pay.
Given that heart attacks can cost up to nearly $1 million to treat[1], and you can't always choose which hospital you're sent to or which doctors treat you, that's a concern.
[1] https://www.cbsnews.com/news/how-much-would-a-heart-attack-c...