If you’re approached by someone who offers “free” genetic testing or cancer screening, turn them down.

Medicare doesn’t cover such tests unless a doctor who’s treating you orders them and they’re medically necessary.

Laboratory representatives have allegedly been taking swabs inside the mouths of Medicare beneficiaries at health fairs, senior centers, residential complexes for older people and veterans centers.

Some seniors are getting cold calls about genetic testing kits. The caller usually offers to send a “free” genetic testing kit and asks only that you return the completed kit with your insurance information — including a Medicare number.

Beneficiaries’ numbers are then used to bill Medicare for thousands of dollars of medically unnecessary genetic testing.

More creative schemes involve sending invitations to an “ice cream social” where seniors hear a presentation about “no cost” genetic testing and/or cancer screenings. During the presentation, seniors are asked for their Medicare numbers — and Medicare is later billed thousands of dollars per test.

Seniors are also being asked for the Medicare numbers and other private information after being brought into health-fair booths for DNA swabs of their cheeks.

In some instances, seniors are given gift cards and told that Medicare will be billed for the tests, even though there’s no physician order for them.

Remember:

>> Don’t give your DNA away to a stranger! Beware of people who cold-call you or show up at your front door uninvited to push genetic tests and cancer screenings. Watch out for people who claim such tests are “100% covered by Medicare.”

Medicare does cover such tests, but only when they are medically necessary and have been ordered by your doctor.

>> Look for charges on your Medicare Summary Notice statements for unnecessary tests or screenings that you didn’t want or weren’t ordered by your doctor.

In general, don’t give out your Medicare number or Social Security number to anyone you don’t know and trust. Be cautious of unsolicited requests for your Medicare or Social Security numbers. If your personal information is compromised, it may be used in other fraud schemes.

Medicare will never contact you out of the blue and ask for your Medicare number or other personal information.

And don’t consent to any lab tests at senior centers, health fairs or in your home. Be suspicious of anyone claiming that you’ll pay nothing for genetic tests and cancer screenings.

If you think you’ve been a victim of fraud, we want to hear from you. Please call us, toll-free, at 800-MEDICARE (800-633-4227).

You can also report suspected fraud at 800-HHS-TIPS.

Or you can contact your local Senior Medicare Patrol, a terrific group which educates people with Medicare about how to avoid health care fraud and abuse.

You can reach Senior Medicare Patrol 877-808-2468 or visit smpresource.org.

One last tip: Enter your phone number on the Do Not Call Registry at donotcall.gov.

Greg Dill is Medicare’s regional administrator for Arizona, California, Nevada, Hawaii and the Pacific territories. You can always get answers to your Medicare questions by calling 800-MEDICARE (800-633-4227).