What to Do If Someone Gets Your Medicare Number

Someone using your Medicare number is identity theft, and you need to act within days, not weeks

If you believe someone has your Medicare number, treat it as identity theft. A thief with your Medicare number can use it to bill Medicare for services you never received, get prescriptions filled in your name, or open accounts using your identity. Medicare will send you notices about claims you did not make — that is often the first sign. Do not ignore these notices. Call Medicare directly at 1-800-MEDICARE (1-800-633-4227) the same day you spot something wrong, and ask them to flag your account for fraud.

You will also need to report the theft to the Federal Trade Commission (FTC) at IdentityTheft.gov. The FTC creates an official record of the theft and gives you a recovery plan. This is not optional paperwork — you may need this record later if a debt collector or creditor contacts you about fraudulent charges. File a police report with your local police department or the FBI's Internet Crime Complaint Center (IC3) if the theft involved online accounts or significant financial loss.

Key Takeaways

Call Medicare at 1-800-MEDICARE when ready if you see claims for services you did not receive or prescriptions you did not fill.
Report the theft to the FTC at IdentityTheft.gov to create an official record and get a recovery plan.
File a police report if the theft involved online accounts, significant money loss, or if you plan to dispute fraudulent debts.
Ask Medicare to place a fraud alert on your account and request a new Medicare number if the theft is serious.
Check your credit report at AnnualCreditReport.com for accounts opened in your name without your permission.

How to spot that your Medicare number has been misused

Medicare sends you an Explanation of Benefits (EOB) for every claim submitted in your name. If you receive an EOB for a doctor visit, hospital stay, or prescription you did not have, that is a red flag. You may also notice bills from providers you have never seen, or collection notices for medical debt you did not incur. Some people discover the theft only when they try to use their Medicare benefits and learn that their deductible is already met or their out-of-pocket maximum is nearly reached — because someone else has already used those benefits.

Another sign is a notice from Medicare saying your account has been locked or restricted. This can happen if Medicare's fraud detection system flags unusual activity. You might also receive a letter saying your Social Security number does not match your Medicare records, or that your address has changed — changes you did not make.

What to do in the first 24 hours

Call Medicare at 1-800-MEDICARE as soon as you realize the theft. Have your Medicare card in front of you. Tell the representative that you believe your Medicare number has been compromised. Ask them to:

Place a fraud alert on your account when ready.
Review your account for any claims you did not authorize.
Tell you whether a new Medicare number has already been issued or whether you need to request one.
Send you a written summary of the fraudulent claims they find.

After you hang up with Medicare, go to IdentityTheft.gov and file a report with the FTC. The website will ask you questions about what happened and when you discovered it. At the end, the FTC will create a personalized recovery plan and give you an Identity Theft Report. read and save this report — you will need it if you dispute fraudulent charges later.

Getting a new Medicare number

Medicare can issue you a new number, but the process is not automatic. Call 1-800-MEDICARE and ask whether your situation warrants a new number. Medicare is more likely to issue a new number if the fraud is extensive, if multiple claims have been filed, or if you are concerned about ongoing misuse. If Medicare approves a new number, they will mail it to you within two to four weeks. Your old number will stop working, but your coverage will not be interrupted.

A new Medicare number does not erase the fraudulent claims already on your old account. Medicare will keep records of those claims so you can dispute them if needed. However, a new number prevents the thief from using your old number to file new claims going forward.

Disputing fraudulent claims and bills

When Medicare sends you an EOB for a claim you did not authorize, you can dispute it. Write a letter to the provider listed on the EOB and to Medicare, explaining that you did not receive the service and did not authorize the claim. Include a copy of the EOB and any other documentation. Send the letter by certified mail so you have proof of delivery. Medicare typically investigates disputes within 30 days.

If a collection agency contacts you about a fraudulent medical debt, do not ignore the call. Send them a written dispute within 30 days of their first contact. Include a copy of your FTC Identity Theft Report. Under federal law, the debt collector must stop collection efforts while they investigate. If they cannot prove the debt is yours, they must remove it from your credit report.

Protecting your Medicare number going forward

Do not carry your Medicare card in your wallet unless you are going to a doctor's appointment. Store it at home in a safe place. Do not give your Medicare number over the phone unless you initiated the call and you know you are talking to a real Medicare representative or your doctor's office. Medicare will never call you unsolicited asking for your number.

Check your credit report at AnnualCreditReport.com three times a year — once every four months — for accounts you did not open. You are may have access to to one free report per year from each of the three credit bureaus (Equifax, Experian, and TransUnion), and you can stagger them throughout the year. If you spot accounts you did not open, dispute them with the credit bureau when ready and file a report with the FTC.

When to contact your doctor or hospital

If the fraudulent claims came from a specific provider — for example, you see multiple claims from a clinic you have never visited — contact that provider's billing department directly. Tell them your Medicare number was used without your permission and ask them to investigate. Provide them with a copy of your FTC Identity Theft Report. The provider may be able to withdraw the fraudulent claims from Medicare on their end, which speeds up the dispute process.

If you are scheduled for an upcoming appointment, call ahead and let your doctor's office know about the identity theft. Ask them to verify your identity using additional information before they process any claims. This prevents the thief from scheduling appointments in your name or accessing your medical records.

Frequently Asked Questions

Will I have to pay for the fraudulent claims?

No. Medicare and your supplemental insurance (if you have it) are responsible for investigating and denying fraudulent claims. You should not receive a bill for services you did not receive. If you do receive a bill, dispute it in writing and include a copy of your FTC Identity Theft Report.

How long does it take Medicare to investigate fraud?

Medicare typically investigates disputed claims within 30 days of receiving your written dispute. However, if the fraud is extensive or involves multiple providers, the investigation may take longer. Ask Medicare for a timeline when you report the theft.

Can I freeze my Medicare benefits to prevent further fraud?

You cannot freeze Medicare itself, but you can request a new Medicare number, which stops the thief from using your old number. You can also ask Medicare to place a fraud alert on your account, which flags unusual activity for review.

What if I discover the fraud months or years later?

Report it to Medicare and the FTC when ready, even if time has passed. There is no time limit on reporting identity theft to the FTC. Medicare will investigate claims going back several years if you can document that you did not authorize them.

Do I need to report this to my supplemental insurance company?

Yes. If you have a Medigap or Medicare Advantage plan, contact them and report the fraud. They may have their own fraud investigation process and can help dispute claims that went through their system.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.