Is balance-billing just a "Virginia thing"?

Poynter Online cites this Richmond Times-Dispatch article about the practice of some doctors and other specialists in hospitals who bill consumers for "the balance" left over after their health insurance has paid, when the hospitals but not the doctors are participating providers with the insurer.

It's a Southwest Virginia/Northeast Tennessee "thing," too - you can't tell whether your anesthesiologist or radiologist or pathologist or whatnot is going to charge you beyond what your insurance will pay, unless you check them out separately. I thought this thing was everywhere.