If you have one of these kinds of medical bills, here’s how—and why—to appeal your health insurance company’s decision.

Whitney Pastorek was surprised when she received a surprise medical bill for more than $400 from a radiologist whose name she didn't recognize.

She'd recently had a mammogram, and for that screening test she went to the same in-network facility she visited annually. She called her insurance company and learned that while the hospital where she checked in, disrobed, and had her scan taken was in her insurance network, the radiologist who read the test—whom she never saw and didn't know about—was out of network. Hence the big bill.

5 Medical Bill Situations You Should Contest

Pastorek called the hospital, asking why they didn't tell her before the mammogram that there would be a charge. She was told that the hospital doesn't always know who will read the films and whether or not that person is in-network. If the hospital didn't know, how was the patient supposed to? Pastorek wondered.

She organized her paperwork and submitted an appeal through her insurer—and she's not the only one. According to a 2021 survey from Lending Tree, three out of four people with medical debt have tried to negotiate the amount they owe. In better news, almost everyone who did so—93%—had a medical bill reduced or dropped altogether.

You'll find out what your health insurance provider thinks you owe when it sends you an Explanation of Benefits (EOB) after your treatment or service. If the bill stems from one of these four situations, you should consider appealing.

It's preventive care

The Affordable Care Act (ACA) dictates that much preventive care—the routine stuff you need to stay healthy, such as flu shots, an annual doctor's exam, and screening tests such as colonoscopies and mammograms—should be covered and not subject to your deductible. That means they may be free to you as long as you have gone to a provider in your insurance company's network and followed guidelines for frequency (such as no more than one exam per year).

It's out of network

Speaking of networks, you can be diligent about going to a provider (such as a lab or a hospital or even an emergency room) that's in your insurance network—and then find out after the fact that the doctor or tech there was out of network. This is what happened to Pastorek.

It's COVID-related testing or vaccines

A variety of federal legislation, including the Coronavirus Aid, Relief, and Economic Security (CARES) Act, dictates that you should not have to pay for most COVID-19 testing or any COVID-19 vaccine. Medical providers can bill your insurance for vaccine administration, but you should not be responsible for what they don't cover. And, if you got sick from Covid-19, contest that, too. "Health insurance providers must waive any cost sharing payments for COVID-19 treatment," says Jill Gonzalez, an analyst with Wallet Hub. ("Cost sharing" is insurance-speak for the part you owe). Even if you are uninsured, you should not be billed for this treatment, she adds. Health care providers can submit a claim to the U.S. Health Resources and Services Administration (HRSA) for reimbursement of these services.

It just makes no sense

Mistakes happen. Your doctor's office could have entered a code wrong. You could have given the hospital old insurance information. You can be charged twice for the same thing. Some studies suggest that as many as 80% of medical bills contain errors. If you see a duplicate charge or your bill is just not right, it is worth looking into.

When you get a bill you want to appeal, you don't have to go it alone. Pastorek felt like her seven-minute telephone hearing went well, but then her appeal was denied. So, she called her congressperson's office. That might seem like a drastic move, but their job is to help constituents, and they have researchers on staff to do so. Once they got involved, Pastorek won her appeal—and didn't owe anything for the mammogram.

Before taking that step, get all your paperwork in order, including dates of treatment, calls made for pre-authorization, and your insurance policy number.

As you get ready to dial, be polite. Big bills are scary, and illness can leave you feeling vulnerable. But the more you can stay on cordial terms with those who answer the phone, the more help you're likely to get.

Start with your provider's office. Your doctor's office deals with insurance companies all day, every day, and may have some insight on your situation.

Next, call your insurance company. Ask why your claim was denied. It might be an easy fix, such as demonstrating that you were pre-authorized for your procedure. If not, the appeals process should be clearly laid out, sometimes with an easy online form. You should be given a timeline of when you can expect to hear back. As Pastorek's experience shows, don't take "no" for an answer. If your appeal is denied, ask what the next steps are.

If you need more help, there are folks who can lend a hand, in addition to your congressperson's office. Try RIP Medical Debt, which raises funds to pay off medical debt and lists regional organizations that may help those in need on its website. The National Patient Advocate Foundation is another good source.

If you strike out on an appeal with your insurer, you can then try to negotiate a lower rate with your provider. Hospitals have teams of folks whose job it is to help people who can't afford their bills. Working with one of these financial services offices will include a lot of forms—such as tax returns and copies of bills from other debt—so it pays, literally, to be organized.

The process can take a long time—hospitals get a lot of these requests. But while the evaluation process is in the works, you won't have to make monthly payments, bills won't go to collections, and won't accrue fees. The Lending Tree study found that 72% of Americans had medical debt that was preventing them from reaching other financial milestones, so, again, know that you are not alone in asking for help.

If you don't have insurance at all, many medical offices will offer you the negotiated rate they have with insurers, so your bill will be lower. (And, if you don't have insurance, check out the state and federal plans through the Marketplace at HealthCare.gov. Monthly premiums could be lower than you think.)

The one thing you don't want to do is just ignore your medical bill because you think it's unfair. In general, unpaid bills to a doctor, lab or hospital don't accrue interest—and they aren't included on your credit report, so they don't affect your credit score. But if you toss them in a drawer hoping they'll go away, the doctor may send them along to a collection agency.

Once a collection agency has them, they can ding your credit report, accrue fees, and the phone calls and letters asking for payment will increase. Starting the appeals process or negotiating a payment plan avoids this scenario…and may make the bill go away for good.