Puck, it is most certainly the provider's responsibility when they make a statement that "Hospital/Care group A is now 100% PPO's for Insurance Plan B"

Then you get a bill from said insurance plan for the aforementioned group that, surprise surprise, there's a Doc within the care provider's group who is NOT a PPO for your health plan.

Not my fault, it's called false advertising in any other field. In healthcare, it's called too bad, you owe us.