Why should I believe in health insurance companies?
To some extent, you do not have to believe in them in order to do business with them. When you buy a health insurance policy, you are entering into a contract. You pay your monthly premium; they pay certain medical bills.
The health insurer has to have enough money on hand in order to offer you this contract. State regulators make sure that they do. Regulators also make sure that the insurer follows the contract they have offered to you. So, if you have a bill denied that you believe should have been paid, the insurer has to review it again and then offer you a hearing with an outside independent person.
Even the contract (policy) that they offer you has to meet a lot of health reform requirements. It’s not like they can bait-and-switch or sell you a knock-off.
I suppose you would need to believe that all of the systems and requirements for the insurer are adequate and will be enforced. That would be your choice, but health insurer bankruptcies are exceedingly rare. For the majority of consumers, the concern is that their claims get paid and not denied.
Long answer — you do not have to believe in the insurance company. You only have to believe that all of the checks in place will work.