Sure, but the recourse for the insurance companies is just to deny it; problem solved. What recourse does the patient have when the insurance company denies a l

Sure, but the recourse for the insurance companies is just to deny it; problem solved. What recourse does the patient have when the insurance company denies a legit claim? Nothing, except hiring legal council when you have a severe illness, probably unable to generate your normal income, with a newly acquired massive amount of debt which affects your ability to borrow. Insurance, by structure, is a conflict of interest. The people you give money to to pay it back when you need it are the same people who get to decide if you get the money back or not. Insurance companies are bound by some legal constraints, but they also have a quite capable legal team to find loopholes in those constraints, and have practiced at this for decades. Even if they're wrong, they can just deny it and fight a long drawn out battle in court hoping you'll just quit, which given your new circumstances, you probably will have to. Your family might be able to continue to fight after you've died though, so there's that. You're simply outmatched.