An older man and woman, the man looking at a paper and the woman looking at the man.

It might begin with what seems like a helpful phone call. Someone who says he’s from Medicare offers you a medical device to ease knee pain or suggests a DNA test to assess your cancer risk. All he needs is to confirm your Medicare number.

But this might be a plan to defraud you—or Medicare—by sending you a device or getting you to take a test you don’t need, and then billing Medicare for it.

In fact, scams like this cost the system about $52 billion in 2017, driving up prices for everyone.

The caller might also steal your medical identity, using the info you supply to impersonate you at a doctor’s office or even gain access to your bank account.

“Unfortunately, fraud is widespread,” says Christina Tetreault, senior policy counsel for Consumer Reports. And scams that target older adults are particularly common.

Some charges that are technically legal can feel like a rip-off, too—like unexpected medical bills from providers you thought accepted your insurance or for services you thought were covered.

Learning about health scams and rip-offs in advance can help you avoid them. Here’s what you should know about a few common cons. 

Medical Equipment Fraud

How it works: Out of the blue, someone calls to say that your doctor has recommended a device—often a back or knee brace—and asks for your insurance info.

Almost everyone has discussed back or knee pain with a doctor, says Amy Nofziger, the director of Fraud Victim Support at AARP, so this may seem plausible. But your doctor would have told you if he or she had ordered a brace for you.

More on Scams and Ripoffs

The problem: Generic back and knee braces may not help; they may even cause additional damage. Plus, scammers offering them can use your insurance info to bill systems fraudulently or assume your medical identity, and they might chase you looking for money.

The fix: Never give your Medicare number or any health information to someone who calls, Nofziger says. If you’re in pain, talk with your primary care physician about your options.

Bills That Take You by Surprise

How it works: For people with private insurance, surprise bills from out-of-network doctors and labs sometimes show up after a hospital visit.

Why? An emergency room, for example, might be in-network but some of its doctors or labs might not be.

If you’re a Medicare beneficiary, you’re generally protected from many surprise medical bills. But some other charges can still shock.

For instance, you might be left with a hefty bill if a hospital keeps you under “observation” status rather than as an inpatient.

Plus, if you need to stay in a nursing home afterward, Medicare will only cover it if you were first an inpatient at a hospital for three nights. And some important services, including long-term care and dental care, aren’t covered by Medicare at all.

The problem: In theory, doctors are supposed to classify people as inpatients if they’re expected to be in a hospital for at least two nights (defined as being there at midnight), says Toby Edelman, a senior policy attorney with the Center for Medicare Advocacy (CMA).

But a 2016 government report found that hundreds of thousands of patients had been categorized as under observation for at least one of the three nights they were in a hospital.

(Inpatient status usually costs Medicare more, so to avoid allegations of overcharging from Medicare auditors, hospitals might classify someone as under observation instead, Edelman says.)

In addition, for people with traditional Medicare coverage, the cost of long-term care and dental care “can be exorbitant and beyond the budgets of many families,” says Tricia Neuman, Sc.D., director of the Henry J. Kaiser Family Foundation’s Program on Medicare Policy.

Even Medicare Advantage plans that include dental care may limit coverage to $1,000 per year or exclude procedures like fillings or crowns. And because your drug plan changes annually, a med that’s fully covered one year might be extremely expensive the next.

The fix: Hospitals are supposed to inform people when they’re under observation status, but even then, there’s not much you can do. CMA advises people and their caregivers to seek a doctor’s help to determine if they should be admitted as an inpatient. Inpatient status is especially important for those who may need nursing home care after a stay. But there’s no appeal process once it’s time to pay.

If you’re buying insurance that covers a service like dental care, Neuman advises a close read to make sure it provides enough coverage to be worth it. Read your drug plan every year to make sure everything you need is covered, and get more info from CR on surprise medical bills  and how to fight them.

Medical Identity Theft

How it works: Scammers trying to get your Medicare number might call with offers of, say, pain management classes, says Nofziger, or plastic Medicare cards, which don’t exist. (They’re paper.) Your medical data could also be stolen in a data breach.

Once a scammer has obtained your medical information, it can be used in a variety of ways. Data thieves might use it to impersonate you while obtaining medical care for themselves or others, bill for fraudulent medical goods or services, or pivot to other types of identity theft.

“The info one needs to commit medical identity theft happens to overlap a great deal with the info needed to open a financial account,” Tetreault says.

The problem: Having your medical data stolen can put you at physical and financial risk. For example, if someone uses your ID, incorrect information could end up in your medical record and you could get the wrong treatment. Or you might get billed for the thief’s medical services.

The fix: Never give your data to someone who calls or sends you an email. In fact, the most important way to safeguard your information is to never give it to anyone unless you initiate contact yourself, says Eva Velasquez, president and CEO of the Identity Theft Resource Center. Caller ID can be thwarted and email addresses can be deceptive. If your doctor or insurer reaches out to you, always call back using a number that you know to be accurate, she adds.

You should also think twice before giving access to your personal medical data to apps, services, or wellness practitioners that aren’t official medical providers, says Natasha Duarte, a policy analyst at the Center for Democracy & Technology. Many of these third parties may not be covered under privacy regulations, and there's a risk that your data could be sold or misused.

And avoid sharing details about health ailments or procedures on social media, says Velasquez, because the info might be used to target you with specific, more personalized scams.

Always read any Explanation of Benefits you receive in the mail to ensure it describes services you actually received, says Velasquez.

If you’re not familiar with a procedure listed, call your insurer and the doctor’s office where the service was given to see whether someone else may have been using your ID.

Report scams or identity theft to the Federal Trade Commission, Tetreault says, and access additional help here.

It’s also important to file a police report, she says, because you might need it to help restore your reputation.

If you’re notified that your identity was stolen in a data breach, follow the instructions you receive. That may include freezing your credit and updating passwords.

Tests and Treatments You Don't Need

How it works: Scammers sometimes reach out to offer screenings that sound like they’ll help keep you healthy, such as DNA tests to assess your risk for cancer or Alzheimer’s, or full-body scans to look for early warnings of disease.

Or they may offer services like stem-cell therapy, which they’ll claim can treat everything from knee pain to diabetes.

Sometimes they’ll call to say a doctor recommended a test; other times you might see this information on flyers, in the mail, in an email, or at a booth at a health fair.

The problem: Many of these tests, including DNA tests and full-body CT scans, are recommended only in very specific circumstances. The tests can also give you incorrect or misleading information that leads to more testing or treatments you don’t need. Stem-cell treatments are almost never recommended; they’re potentially illegal and sometimes dangerous.

In some cases, scammers offering these services may also steal your identity, bill Medicare fraudulently, or ask for money.

The fix: Check with your doctor before getting any screening or treatment.

Editor’s Note: This article also appeared in the October 2019 issue of Consumer Reports On Health