A trip to the emergency room can be traumatic enough, but researchers warn that many insured patients may be in for another shock when the medical bills arrive.
Even if patients go to a hospital included in their health insurance network, the emergency room physicians might not be. That could mean an unexpected expense.
"We all assume that when you have an in-network hospital that people working (there) also are in network, and that's not the case," Yale assistant professor Zack Cooper said.
Cooper and fellow Yale researcher Fiona Scott Morton analyzed insurance claims for more than 2 million ER visits around the country. They found that roughly 2 of 10 in-network visits involved a doctor not in the patient's insurance network.
"The result is a large physician bill that the insurer doesn't cover or only partially covers, leaving the patient to pay the balance," they wrote in Thursday's New England Journal of Medicine.
Patients might be liable for an average balance of around $622, the researchers estimated. They didn't calculate how many patients in their data sample were hit with a surprise bill.
But the mere presence of an out-of-network doctor doesn't guarantee financial doom. That will depend, in part, on the patient's insurance coverage. And some states like New York have laws that offer some protection against surprise bills, although the extent of that protection varies.
Patients who receive a larger-than-expected bill for emergency care may have limited options to change it.
They can ask that the claim be processed again as in-network care since the patient had no way of knowing the doctor was out of network, said Erin Singleton of the nonprofit Patient Advocate Foundation. Or they can try to negotiate a lower bill.
"Negotiation is always an option and helps the patient avoid dings against their credit," said Singleton, whose foundation helps patients deal with medical debt.
Health insurers have been offering more plans with narrow networks in recent years, especially on the Affordable Care Act's public insurance exchanges. Insurers form networks of doctors and hospitals, in part, to gain some leverage for negotiating reimbursements. Usually patients pay a bigger share of the bill for any care sought outside these networks.
A hospital's ER doctors might not be in the patient's insurance network because the hospital contracts with them for their work, and those doctors make separate agreements with insurers.
While many people have become accustomed to checking on a doctor's network status, bills from outside providers can still pop up, especially from anesthesiologists after a surgery.
Cooper said in an interview that surprise bills from emergency care can be "particularly egregious" because the patient may have no way of finding out beforehand the network status of the doctor on duty to treat them that day.