If someone has your Medicare number, they can bill the federal government for medical services you never received, obtain prescription drugs or equipment in your name, enroll you in a health plan you didn’t choose, and use the number as a stepping stone to broader financial identity theft. Your Medicare Beneficiary Identifier (MBI) is the 11-character mix of letters and numbers printed on your card, and it works as the key to your entire Medicare account.1Centers for Medicare & Medicaid Services. Medicare Beneficiary Identifiers Because Medicare processes more than a billion claims a year, misuse can go unnoticed for months if you aren’t watching for it.
Billing Medicare for Services You Never Received
This is the most common use of a stolen Medicare number. A dishonest provider or a criminal ring submits claims for office visits, lab work, or durable medical equipment that never happened. Medicare pays, and you don’t find out until you look at your statements. The official Medicare fraud guide specifically warns that dishonest providers use beneficiary numbers to get paid for services they never delivered.2Medicare. Protecting Yourself From Fraud
The volume matters. Medicare reimburses quickly and at scale, so a single MBI can generate thousands of dollars in fraudulent claims before anyone notices. That is why scammers work so hard to get numbers, and why the “free” back brace, genetic test, or diabetes supply offered at a health fair almost always turns out to be a pretext to collect your MBI.
Getting Drugs and Equipment in Your Name
A stolen MBI lets someone fill prescriptions or order medical equipment under your identity. The immediate cost lands on Medicare, but the longer-term damage lands on you: those fraudulent prescriptions and diagnoses end up in your medical records. If a scammer fills opioid prescriptions in your name, that drug history can follow you into future medical care and influence how your own doctors treat you. Wrong entries about allergies, medications, or conditions can also lead to dangerous decisions in an emergency, when a physician relies on the chart in front of them.
Switching You Into a Health Plan You Didn’t Choose
Scammers use stolen Medicare numbers to enroll beneficiaries into Medicare Advantage or Part D plans without their knowledge. Medicare warns that no one should join you into a health or drug plan over the phone unless you called and asked for that help.3Medicare.gov. Reporting Medicare Fraud and Abuse An unauthorized switch can change your doctors, your drug coverage, and your out-of-pocket costs overnight, and many people don’t discover it until they try to use their existing plan and find out it has been canceled.
Opening the Door to Wider Identity Theft
A Medicare number by itself is not a Social Security number, but it is rarely stolen alone. Combined with your date of birth and address, it gives a thief enough to open credit cards, take out loans, or commit financial fraud in your name. At that point the damage spreads well beyond Medicare.
How Fraud Can Eat Into Your Own Benefits
This is the part that catches most people off guard. Fraudulent claims don’t just cost Medicare money. They can directly reduce the benefits available to you. Several Medicare services have built-in limits, and if Medicare’s records show those services were already provided, your real claims for the same services can be denied.4Senior Medicare Patrol. Consequences to Beneficiaries Skilled nursing facility days, home health visits, and certain therapy services all have coverage caps that fraudulent billing can prematurely exhaust. You could end up fighting for coverage of care you genuinely need because, on paper, you already “received” it.
Fraudulent claims can also plant inaccurate diagnoses in your records. A false diagnosis of a serious condition can affect your ability to obtain life insurance or long-term care coverage later.
How to Tell If Your Number Is Being Used
Your Medicare Summary Notice (MSN) is the single most important fraud-detection tool you have. It lists every service billed to Medicare on your behalf. Compare it with what you actually received, and check for tests, items, or services you didn’t get.2Medicare. Protecting Yourself From Fraud Unfamiliar providers, locations you’ve never visited, services you didn’t receive, and wrong dates are the red flags. You don’t have to wait for the paper notice; log into your account at Medicare.gov to track claims in real time.
Warning signs outside your statements:
- Unsolicited contact from someone claiming to represent Medicare and asking for personal information. Medicare will only call and ask for personal information if you initiated the contact first, such as leaving a message or filing a fraud report.3Medicare.gov. Reporting Medicare Fraud and Abuse
- “Free” medical equipment, genetic tests, or supplies offered in exchange for your Medicare number.2Medicare. Protecting Yourself From Fraud
- Medical equipment or supplies arriving at your door that you didn’t order.
- Pressure tactics, threats to cancel benefits, or urgency around accepting a service.
What to Do If Your Medicare Number Has Been Used
Report It and Get a New MBI
Call 1-800-MEDICARE (1-800-633-4227) as soon as you suspect fraud. The hotline can help you understand suspicious charges, flag your account, and issue a new Medicare number if yours has been compromised.5Medicare. Contact Medicare If you have a Medicare Advantage or Part D plan, contact that plan directly as well, since it processes its own claims.
Also report to the Department of Health and Human Services Office of Inspector General, which investigates Medicare fraud. File a complaint online or call 1-800-HHS-TIPS (1-800-447-8477).6U.S. Department of Health and Human Services Office of Inspector General. Submit a Hotline Complaint
Protect the Rest of Your Identity
If your Medicare number was stolen alongside other personal information, go to IdentityTheft.gov to create a personal recovery plan tailored to the type of theft you experienced.7Federal Trade Commission. Identity Theft A Recovery Plan For medical identity theft specifically, the FTC advises reporting billing errors to all three credit bureaus using the steps generated by IdentityTheft.gov.8Consumer Advice (Federal Trade Commission). What To Know About Medical Identity Theft
Consider a credit freeze, which is stronger protection than a fraud alert. A freeze blocks lenders from accessing your credit report, so no one can open new accounts in your name (including you, until you lift it). It lasts until you remove it, costs nothing, and doesn’t affect your credit score, but you have to contact Equifax, Experian, and TransUnion separately. A fraud alert is lighter: an initial alert lasts one year and tells lenders to verify your identity, and you only need to contact one bureau, which notifies the other two. Identity theft victims who have filed a report at IdentityTheft.gov or with police can place an extended fraud alert lasting seven years.9Consumer Advice (Federal Trade Commission). Credit Freezes and Fraud Alerts
Clean Up Your Medical Records
Fraudulent entries in your medical records can affect future care, so it’s worth the effort to correct them. Under federal privacy regulations, you can request that any healthcare provider amend your medical records. The provider must act on your request within 60 days, though it can take a single 30-day extension with written notice.10eCFR. 45 CFR 164.526 – Amendment of Protected Health Information Providers generally don’t delete fraudulent entries outright; they append a correction so the record is accurate and complete. Submit your request in writing, explain that the entries resulted from identity theft, and keep copies. Use your Medicare Summary Notices to identify every provider and facility where fraudulent claims were filed, because each one will need a separate request.
How to Keep It From Happening Again
Treat your Medicare card like a credit card. Don’t carry it in your wallet unless you’re going to a medical appointment, and never give the number to anyone who contacts you unsolicited. Share it only with your doctors, your insurer, or trusted community organizations like your State Health Insurance Assistance Program (SHIP).2Medicare. Protecting Yourself From Fraud Review every Medicare Summary Notice, check your Medicare.gov account between notices, and shred documents that show your MBI before throwing them away. If someone calls claiming to be from Medicare, hang up and call 1-800-MEDICARE yourself to verify. The Senior Medicare Patrol program offers free help spotting and reporting fraud through smpresource.org.