The USA medical insurance system is missing a "stick" for such bogus rejections. Unduly denying a claim should result in a fine big enough to be felt in the company balance sheet, that is the only way to change companies' behaviours.
What if we just don't have a stick. The government or a company they hire is the party that reviews claims. The insurance contacts must have standardized terms and conditions.
This probably wouldn't even really hurt the insurance companies. They would not need to compete with each other by denying claims on the backend to provide lower prices on the frontend.
, missing some kind of harsh