As the air ambulance industry has grown, so too have complaints about cost and the lack of regulations.

Patients flown by an out-of-network provider have received bills for tens of thousands of dollars after their insurance plan makes its payment.

Air ambulance companies argue insurers, Medicare and Medicaid don't cover their costs, so they have to send huge bills to some patients. Payers say the companies won't reveal their actual costs, so they can't determine what a fair payment might be.

The federal Airline Deregulation Act prevents states from interfering with the fares, routes and services of air carriers. An initial effort to let states regulate air ambulances recently failed in the U.S. Senate.

In the meantime, consumers are urged to educate themselves about what, if any, air ambulance insurance coverage they might have and whether the provider in their area is in their insurance network.