These 5 medical services will put a dent in your savings

Here's a surprise everyone hates: an unexpected medical bill when you thought your insurance would cover everything.

Patients often face steep bills when they wind up with a provider who isn't in their network. In-network doctors and facilities have an agreement with your health plan to offer contracted rates to members; your copayments and deductibles are likely lower with them.

You'll pay a steep price for going outside that network.

"Out-of-network costs often don't even go toward your deductible, or your deductible is so huge that it breaks the bank," said Carolyn McClanahan, MD, director of financial planning at Life Planning Partners in Jacksonville, Florida, and a former physician.

One in 5 inpatient hospital admissions that start in the emergency room may lead to an unexpected bill, according to December 2016 research in Health Affairs, a health-care policy journal.

"In any in-facility service, whether you go through the emergency room or check in through the front door to stay for a procedure, that's an opportunity for a surprise bill," said Karen Pollitz, senior fellow, specializing in health reform and private insurance at the Kaiser Family Foundation.

"It's likely a team of health professionals may participate in your treatment and you will have nothing to say about who those people are," she said.

Expect a large bill if you see these physicians and experts out of network.

The doctor who puts you under is also most likely to cause your wallet some pain, too.

This January, research from Johns Hopkins University showed that anesthesiologists charge up to six times what Medicare pays them, making them the doctors with the highest cost markups. The study used Medicare's reimbursement to physicians as a benchmark.

Know who's reading your X-rays.

Surprise bills from out-of-network radiologists averaged $5,406, according to a 2012 study from New York's Department of Financial Services. On average, insurers covered $2,497 of this expense, but consumers were on the hook for the remainder.

Data from Johns Hopkins University showed that emergency physicians charge four times what they're paid by Medicare, making their bills higher than expected if they aren't in network.

"You get whoever shows up to the emergency, including the ambulance, the hospital where you end up and the emergency room doctor," said Pollitz.

In 2014, the Center for Public Policy Priorities in Austin, Texas, performed an analysis of three insurers with the most market share in the Lone Star State. The study revealed that between 21 and 45 percent of in-network hospitals for these three insurance companies had no in-network emergency room doctors.

Let's say your doctor extracted some tissue from you and sent it off to a pathologist for analysis. You may be on the hook for a large bill if they are out of network.

These experts charge four times what they're paid by Medicare, according to Johns Hopkins.

"If there's going to be lab work, let the physician know that you want to make sure they know your plan rules," said Steve Wojcik, vice president of public policy at the National Business Group on Health, an organization that represents large employers.

In the best of circumstances, you've planned out your panel of experts before you go for surgery, but if a complication arises, an assistant surgeon may pop in to help.

Expect to pay if this person is out of network.

In its analysis of surprise medical costs, New York's Department of Financial Services found that the average bill for these assistant surgeons was $13,914, of which insurers paid $1,794.