Your Medicare number, Medicare Beneficiary Identifier (MBI) should be treated like a credit card number. Share it only with doctors, pharmacies, and other providers you've chosen, or with people helping you manage your Medicare benefits. Don't carry the card in your wallet unless you're heading to an appointment. 

Since the transition from the old Health Insurance Claim Number, based on your Social Security Number to the Medicare Beneficiary Identifier (MBI), a unique, randomly assigned 11-character identifier used for Medicare transactions such as billing, eligibility verification, and claim processing, scammers are getting creative.  

Recent data breaches have precipitated the issue of 1.3 million Medicare Identifier numbers. Before you respond to any notice of a change, verify that you are receiving a new number. These creative scammers are using this transition as an opportunity to take advantage of you with fake cards. 

The most common scammer tactics to watch for: 

  • Fake card activation calls: Someone calls claiming you need to "activate" or "renew" your Medicare card and asks for your number to process it. Medicare never requires card activation. 
  • Free equipment or testing offers: A caller offers free medical supplies, genetic testing, or screenings you didn't ask for. The real goal is getting your Medicare number so they can bill Medicare for services you never received. Never give your number to anyone who calls you. You can supply that in person at the medical facility. 
  • Threats to cancel coverage: A caller says there's a problem with your account, and your benefits will end unless you verify personal information immediately. Medicare does not operate this way. Refuse to be intimidated. 

The core rule: Medicare will not call you out of the blue to ask for your MBI, Social Security number, or bank information. If someone does, hang up. That call is not from Medicare. 

If you receive a new card in the mail, know that an official Medicare card is old-school, a red, white, and blue paper card. Some of the scam cards are laminated plastic with holograms. Even if the card looks legitimate, the first thing you should do is log in to your Login.gov account to check your Medicare number. 

If you discover unauthorized claims on your Medicare account or believe someone has your MBI, act quickly. The damage from medical identity theft goes beyond money — incorrect medical records can follow you into future treatments, creating real health safety risks. 

Start by calling 1-800-MEDICARE (1-800-633-4227) to report the fraud. Medicare may decide to issue a new MBI. Then report the fraud to the HHS Office of Inspector General at 1-800-HHS-TIPS (1-800-447-8477) or through their online complaint form. 

The Federal Trade Commission recommends three additional steps for medical identity theft of any kind. First, contact your health insurer's fraud department and request your Explanation of Benefits statements so you can flag charges you don't recognize. Second, file a report at IdentityTheft.gov to get a personalized recovery plan that walks you through fixing credit issues, disputing fraudulent accounts, and sending pre-filled letters to the right agencies. 

Medicare does not recommend that you reach out to the providers where the thief used your information, they may be the actual source of the fraud, and your interaction may compromise more of your information.