[jihoon796]

Firstly, why would a hospital relinquish control of payment to the patient? The hospital is the one getting paid, after all, and they want to maximize their profits (aka get paid as much as they can).

Secondly, if a provider doesn't negotiate with an insurance company, the insurance company would naturally reimburse a lot less. In the U.S., the lion's share of provider revenue comes from insurance companies instead of patient self-pay, so they have less leverage to negotiate here. Of course, a large hospital system could just say "screw you, we won't join your network" (in which case they have the upper hand, since people are more likely to pay insurance premiums for plans that include their current doctor/hospital).