Surprise medical bills are a problem for a very large number of hospital patients. They occur when a patient seeks treatment at a hospital that is in the patient’s health insurance company network, under the mistaken belief that everything done there will be covered under the insurance agreement.

The surprise comes when an in-network hospital provides out-of-network services and bills the patient for more than they would ordinarily pay. Hospitals usually do nothing to alert patients about these services before the final bill is presented.

In one recent survey, 43 percent of all emergency department visits and 42 percent of all hospital admissions resulted in some out-of-network charges. They averaged $628 and $2,040, respectively. In some cases the bills were horrendous, including a $50,000 allergy test and a $500,000 dialysis bill.

In most cases patients are completely unaware that some of the care being delivered is not in their insurer’s network until they see a bill.

So, what can be done? There are several possibilities.

The Arbitration Solution. Under a bill proposed by Senator Bill Cassidy (R-LA) and others, patients would be held harmless and would pay only in-network rates. That means any higher (surprise billing) amounts would have to be divided between the providers and the insurers. If they couldn’t agree on a division, either party could seek arbitration. (See the summary here.)