If the need to go the emergency room suddenly arises, your first instinct is likely to be a phone call to 911—not to wonder how much an emergency room visit may cost you. And in an emergency, getting the right care, and getting it fast, should be the focus.

“If you’re having a heart attack, you’re not going to ask if the doctor treating you takes your insurance,” says Karen Pollitz, a senior fellow at the Kaiser Family Foundation.

But be aware: That potentially lifesaving trip to the emergency room may have a high price tag attached to it. A Kaiser-New York Times survey of insured and uninsured people who had difficulty paying medical bills found that ER bills accounted for the largest portion of what they owed.

Going to a hospital that takes your insurance may not prevent you from getting unexpected big bills. Here's why: About two-thirds of emergency room doctors are independent contractors, who may not be in your insurance plan, according to the American College of Emergency Physicians. And any out-of-network doctor or laboratory may later bill you for whatever your insurance doesn’t cover, a practice called balance billing. “There can be a whole cast of providers involved, some you never even meet, who send you a bill,” says Pollitz.

In addition, if the ambulance company that transports you to the emergency room doesn't take your insurance, your out-of-network costs could be over $2,000, depending on factors such as where you live and the level of care you receive before you get to the hospital. A breathing tube, for example, may bump up the price. And if your insurer doesn’t consider the ambulance ride essential, you may be on the hook for even more money

You can’t completely protect yourself from these kinds of surprising medical bills, and you never want to put cost concerns ahead of getting care during an emergency. But these strategies may help.

Understand Your Insurance Policy

Ask your insurer for documentation on what the plan will and won't cover if you need emergency care. (The insurer's website or handbook may not be up to date). For example, get clarity on your ER copay and coinsurance and on what the plan will cover if you’re not admitted. Your insurer can also tell you which area hospitals take your insurance. You can then ask the billing department at your hospital of choice whether the ER doctors participate in your insurance plan.

And because most insurers cover medically necessary ambulance rides, know how your plan defines that—typically, it means you are unconscious, bleeding heavily, or in severe pain.

To find out more on what other states are doing and share your story, go to Consumer Reports' End Surprise Medical Bills site.

Questions to Ask at the Hospital

When you call 911, a dispatcher will send the closest available ambulance, so there’s no way to know whether it will be in your insurance network. And though you can request a particular hospital, it's the ambulance staff’s call—and usually they will choose the closest facility that’s properly equipped to treat you, says Scott Moore, President of EMS Resource Advisors and a consultant to the American Ambulance Association

In certain situations, say you have a head trauma and need a CAT scan, you'll go to the hospital that the paramedics know has the equipment you need for the appropriate treatment. "If I drive past a hospital, I better have a good reason that I went to another one farther away," says Moore, who is also an EMT. If someone else calls an ambulance and you don't need it, you typically won't be billed unless you get transported, says Moore, though you may be charged for services provided on the scene. 

Under the Affordable Care Act, if you need emergency care, your co-pay or co-insurance cannot be higher than your in-network rate, even at out-of-network hospitals. But the law doesn’t prevent out-of-network providers from billing you for the remainder after you’ve received care.

At the hospital, you or the family member or friend who ideally goes with you, will need to fill out admission forms. This is the time, if it's possible, to request an in-network doctor or other service provider. At discharge, make sure you or your companion requests and keeps all paperwork, including an itemized printout of charges.

What to Do If You Get an Out-of-Network Bill

You'll probably get separate bills from each out-of-network provider involved in your emergency room care. Pay nothing until you get explanation of benefits (EOB) statements from your insurer; these tell you what the plan has covered and what your portion may be. Then, compare bills and EOBs to make sure you received the services noted and have your insurer confirm that providers who sent bills are indeed not in your plan.

Then, work on getting those bills covered. Ask your insurer whether it’s willing to do so. You can also contact the healthcare providers who billed you and ask them to settle for what insurance has already paid them. "Some doctors will negotiate with you," says Pat Palmer, founder and CEO of Medical Billing Advocates of America, based in Roanoke, Va. Your insurer may also negotiate with the doctor on your behalf if you request it.

If the insurer and healthcare providers won't budge, file an appeal with your insurance company. To bolster your case, ask your primary care doctor or specialist for a letter stating that your ER treatment was medically necessary. The Patient Advocate Foundation offers guidance at no charge. Professional claims consultants will also help for a fee or percentage of the amount reimbursed. You can find claims consultants via the National Association of Healthcare Advocacy Consultants or the Alliance of Claims Assistance Professionals.

Finally, be aware that 23 states are working toward or already have some consumer protections against surprise medical bills. For example, in New York, these bills can now go through an independent dispute resolution process if the health plan and provider don’t agree on payment amount. To find out more on what other states are doing, how to file appeals at the state level and share your story, go to Consumer Reports’ End Surprise Medical Bills site.