CHARLOTTE, N.C. -- In September, Erika Giovanetti had a scare people have unfortunately become familiar with. She was potentially exposed to someone with COVID-19.

Being safe, rather than sorry, she went to get tested.

“Without really putting too much thought into it, I booked an appointment at the nearest urgent care center,” Giovanetti says.

Within an hour, her tests were negative, and she was able to head home. But a few weeks later she got a surprise.

“I refreshed my email and saw I did in fact get a bill from the urgent care center. It was for $153, so it was nothing to sneeze out,” Giovanetti says.

COVID-19 tests are supposed to be free, so Giovanetti, who writes about medical bills as part of her job, was caught off guard.

“[I] called the provider and called my insurance, and was able to get it sorted out but it was still pretty murky why I was charged in the first place,” Giovanetti says.

She's not the only one caught in the confusion. Sterling Price is a research analyst at Lending Tree in Charlotte.

He says the reason is often because the provider hasn't posted the price of the test on their website. That leaves the insurance company with no information.

“It's a weird kind of last line in the CARES Act that is actually saying you need to see a posted price online and if it's not there then there's a misconnect between the two providers, and the patient is left with the bill,” Price says.

Price says that can cost up to $850 for some tests. The good news, Price says, is if you do get charged and you contact your insurance company the bill should be removed.

But he says there are things you can do ahead of time.

“Do the research for these facilities beforehand, make sure you get the posted price, and then try to match it up with the facility, and then try to match it up with the itemized receipt,” Price says.

Giovanetti was able to get her bill removed, but the process was a learning experience.

“I think that the more frustrating part about this whole experience is knowing that somebody who might not have the same knowledge set as me of these topics is just going to see a bill and pay because they don't feel like they have a choice,” Giovanetti says.

Mistakes by an insurance company and healthcare provider, as well as confusion about is covered, can also result in someone being charged for a COVID-19 test, according to Consumer Reports.

Most counties and state public health departments and some pharmacies offer free coronavirus testing. Contact your local public health department or your doctor to find a free testing site.