Medicare fraud: how to spot it, check your MSN and report it

Medicare fraud does not usually look like a crime. It looks like a friendly phone call offering a free back brace, a "Medicare representative" at the door, a test you never had on a statement you never read. The Centers for Medicare & Medicaid Services (CMS) says Medicare fraud and medical identity theft can cost taxpayers billions of dollars each year, and its own fact sheet puts it plainly: you are the first line of defense.

This guide explains how to read your Medicare Summary Notice and your online claims, the warning signs CMS lists, what Medicare plans are not allowed to do when they sell to you, how to protect your Medicare Number, and exactly how and where to report a problem. It is based on CMS's booklet Protecting Yourself From Fraud (February 2025), its fact sheet 4R's for Fighting Medicare Fraud (July 2024) and the Medicare & You 2027 handbook.

What medical identity theft is

CMS defines medical identity theft as someone stealing or using your personal information, like your name, Social Security Number or Medicare Number, to submit fraudulent claims to Medicare and other health insurers without your permission. A dishonest provider who gets your number can bill Medicare for services it never delivered. You may not notice anything at all unless you look at the claims made in your name.

Medicare & You 2027 says Medicare is improving how it fights fraud, including using AI tools to detect fraud early and stop improper payments, but it still asks people with Medicare to check their statements, guard their card and report anything suspicious.

The 4 R's: CMS's short version

The rest of this guide goes through each step in detail.

Record: keep your own log

CMS suggests recording the dates of your health care services on a calendar, along with any tests, items and services you get, and saving the receipts and statements from your providers. That gives you something to compare against what Medicare was billed. If keeping track is hard, CMS says you can ask a friend or family member to help. A simple notebook works: the date, the doctor or supplier, and what was done, like "blood work" or "X-ray of left knee."

Review: read your Medicare Summary Notice

If you have Original Medicare, you get a Medicare Summary Notice (MSN). Medicare & You 2027 explains that it lists all the services billed to Medicare and shows what Medicare paid and what you may owe the provider. It is not a bill. You get it in the mail at least twice a year, unless you sign up to get it electronically.

When you read an MSN, CMS says to check that:

• You actually got every service, supply and piece of equipment listed.
• Neither you nor Medicare was billed for anything you did not get.
• If you were in the hospital, the admission date, discharge date and diagnosis are correct.
• You recognize every provider named on it.

The MSN does other work, too. It tells you how to appeal if you disagree with a decision not to cover a service, and it shows whether you are in the Qualified Medicare Beneficiary (QMB) program. If you are, Medicare providers are not allowed to bill you for Part A or Part B deductibles, coinsurance or copayments. See our guide on how to appeal a Medicare denial and our page on Medicare Savings Programs.

If your MSN shows a denial you disagree with

A denied claim is not fraud, but the MSN is also where you start an appeal. Medicare & You 2027 lists the steps for Original Medicare:

1. Get the MSN that shows the item or service you are appealing.
2. Circle the items you disagree with and write why, either on the MSN or on a separate sheet attached to it.
3. Add your name, phone number and Medicare Number, and keep a copy for your records.
4. Send the MSN, or a copy, to the Medicare Administrative Contractor listed on it, with any supporting information, like notes from your provider. You can use Form CMS-20027 instead.
5. File by the date on the MSN. If you miss it, you may still get a decision if you can show good cause, like a disability, illness or accident that delayed you.

You will generally get a decision within 60 days after the contractor gets your request, and if Medicare will cover the item, it is listed on your next MSN. The handbook also suggests asking your doctor, supplier or other provider for information that makes your appeal stronger, and keeping a copy of everything you send.

Do not wait for the mail

CMS stresses checking early: the sooner you find and report errors, the sooner you can help stop fraud. You have faster options:

• Your Medicare account. Log into (or create) your secure account at Medicare.gov. Medicare & You 2027 says Original Medicare claims are generally available online within 24 hours after processing. You can also download your claims data by selecting your name in the top right menu and then "Download my claims & personal data" under "My Account."
• Electronic MSNs. Sign up at Medicare.gov/my/eMSN. Medicare then sends you an email each month when your MSNs are available in your account, instead of paper copies.
• 1-800-MEDICARE (1-800-633-4227). The automated phone system gives information on Original Medicare claims processed in the past 12 months, and you can talk or chat with a person 24 hours a day, 7 days a week, except some federal holidays. TTY users can call 1-877-486-2048.

New for 2027, Medicare.gov also lets you log in through ID.me, CLEARme.com or Login.gov, free identity verification services that the handbook says help prevent fraud and keep your information secure. Once you connect one of them to your existing account, you can no longer log in with your old Medicare username and password.

In a Medicare Advantage or drug plan

If you have a Medicare Advantage Plan, another Medicare health plan or a drug plan, you do not get an MSN for services the plan covers. Check the statements your plan sends you the same way.

If a charge looks wrong

Not every mistake is fraud. If you know the provider, CMS suggests calling the office to ask about the charge; the staff may explain what you got, or find an error that needs fixing. Medicare & You 2027 adds that you can ask a provider or supplier you know for an itemized statement, which it should give you within 30 days. If you have contacted the provider and still suspect Medicare was charged for something you did not get, or you do not know the provider on the claim at all, call 1-800-MEDICARE.

Warning signs CMS lists

Be suspicious of anyone who tells you

• The equipment or service is free, and they only need your Medicare Number for their records.
• Medicare wants you to have the item or service.
• They know how to get Medicare to pay for it.
• The more tests they provide, the cheaper the tests become.

Be suspicious of providers, suppliers or facilities that

• Do not charge copayments without checking on your ability to pay.
• Advertise "free" consultations to people with Medicare.
• Bill Medicare for services, supplies or equipment you did not get.
• Put the wrong diagnosis on the claim.
• Bill Medicare for tests you got as a hospital inpatient or within 72 hours of your admission or discharge.
• Claim they represent Medicare or a branch of the federal government.
• Use pressure or scare tactics to sell high-priced medical services or diagnostic tests, or threaten to withhold services.
• Offer money or kickbacks to use their services, join their plan or let them use your Medicare Number.
• Use phone calls and door-to-door selling as marketing tools.
• Offer non-medical transportation, like trips to the grocery store, or housekeeping as Medicare-approved services.
• Bill home health services for patients who are not confined to their home, or for Medicare patients who still drive a car.
• Ask you to contact your doctor and request a service, supply or equipment you do not need.
• Bill Medicare for a back brace or other orthotics, a power wheelchair or scooter, or genetic tests you do not need.

The home health item connects to Medicare's homebound rule, explained in our home health care guide.

Protect your Medicare Number

CMS's advice is to treat your Medicare card like a credit card. Do not give your Medicare Number or Social Security Number to anyone except your doctor or other Medicare provider, insurers acting on your behalf, or trusted people in the community who work with Medicare, like your State Health Insurance Assistance Program (SHIP). Never give it in exchange for free medical equipment, money, gifts or any other offer, never let someone else use your card, and never use another person's.

When Medicare will actually call you

Do not share personal information with anyone who contacts you by phone, email or in person unless you gave them permission in advance. CMS says Medicare, or someone representing it, will only call and ask for personal information in these situations:

• A Medicare health or drug plan can call you if you are already a member. The agent who helped you join can also call you.
• A 1-800-MEDICARE representative can call you if you called and left a message, or a representative said someone would call you back.
• If you filed a report of suspected fraud, someone representing Medicare may call to follow up.

Anyone else who calls out of the blue and asks for your Medicare Number: hang up and call 1-800-MEDICARE yourself. And remember that Medicare and Medicaid do not send representatives to your home to sell products or services.

If your card or number is compromised

• Call 1-800-MEDICARE if your Medicare card is lost or you believe someone else is using your Medicare Number.
• For a lost Social Security card, visit SSA.gov/number-card/replace-card.
• If you get Railroad Retirement Board benefits, visit rrb.gov or call 1-877-772-5772.
• If you think you gave personal information to someone you should not have, call the Federal Trade Commission's ID Theft Hotline at 1-877-438-4338 (TTY 1-866-653-4261), or visit ftc.gov/idtheft to learn more and file a report.

What Medicare plans are not allowed to do

CMS lists rules every Medicare plan must follow when it markets to you. Plans are not allowed to:

• Ask for your Social Security Number, bank account number or credit card information over the phone. The exception: if you applied for Extra Help with Part D, someone from the plan may contact you if information is missing from your application.
• Come to your home uninvited to sell or endorse any Medicare-related product.
• Offer you cash to join or give you free meals while marketing to you.
• Enroll you in a Medicare drug plan over the phone unless you call them.
• Steer you into a particular plan.
• Give incorrect information about their plan type, or use unproven claims like "the best" or "highest ranked."
• Ask you for payment over the phone, internet or in person. The plan must send you a bill.
• Call you, unless you are already a member. If you are, the agent who helped you join can call.
• Sell you a non-health product, like an annuity or life insurance policy, while selling a Medicare health or drug plan.
• Make an appointment to tell you about their plan unless you agree in writing or on a recorded call, and during the appointment, sell anything beyond the products you agreed to hear about.
• Talk to you about their plan where you get health care, like an exam room, hospital patient room or pharmacy counter.
• Market or enroll you during an educational event, like a health fair or conference.
• Offer an unapproved Medicare plan, or use false information to mislead you into joining one.

Independent agents and brokers who sell a plan must be state-licensed, and the plan must tell the state which agents sell its plans. CMS also says to read and understand documents before you sign them, and to ask a friend or family member to explain anything you do not understand.

If you think a plan is breaking these rules, call 1-800-MEDICARE or your SHIP (shiphelp.org). Call 1-800-MEDICARE as well if you think you were enrolled in a plan without your consent, or that a plan or its agent misled you. Our guide to Original Medicare vs. Medicare Advantage explains the choice itself.

Report: how and where

If you suspect Medicare fraud, CMS lists these ways to report it:

Have this ready before you call

• Your name and Medicare Number, as listed on your red, white and blue Medicare card.
• The name of the doctor, supplier or facility you think committed fraud, and any identifying information you have about them.

If the fraud is tied to a specific claim, also have:

• The service or item you are questioning.
• The date you supposedly got it.
• The amount Medicare approved and paid.
• The date on your MSN or claim.
• Why you think Medicare should not have paid, and any other information that shows it.

If it is not tied to a claim, have a description of what happened, the place, date and time, and any other evidence you have.

Free local help: Senior Medicare Patrol

The Senior Medicare Patrol (SMP) program educates and empowers people with Medicare to take an active role in their health care, including detecting and preventing fraud and abuse. Find your local SMP at smpresource.org or call 1-877-808-2468. Medicare.gov/fraud has more information.

CMS's do's and don'ts

Do

• Protect your Medicare Number and Social Security Number.
• Remember that nothing is ever "free," and do not accept money or gifts for free medical care.
• Ask questions. You have a right to know everything about your medical care, including the costs billed to Medicare.
• Learn what a provider can and cannot bill to Medicare. Medicare.gov/basics/your-medicare-rights explains your rights.
• Use a calendar for appointments and tests, then check your statements carefully.
• Be wary of providers who say an item is not usually covered but they "know how to bill Medicare."
• Understand how a Medicare health or drug plan works before you join.
• Check your pills before you leave the pharmacy: the right medication, brand-name or generic as expected, and the full amount. If you do not get your full prescription, tell the pharmacist.
• Report suspected fraud.

Don't

• Let anyone except your doctor or other Medicare providers review your medical records or recommend services.
• Ask your doctor for a service you do not need, or let anyone persuade you to see a doctor for care you do not need.
• Accept medical supplies you did not expect, your doctor did not prescribe, or that come from someone you do not know.
• Be influenced by television, internet and radio ads about your health.
• Give your Medicare card, Medicare Number, Social Security card or Social Security Number to anyone except your doctor or a trusted Medicare provider.

A short checklist

• Create your Medicare.gov account and sign up for electronic MSNs.
• Keep a log of every appointment, test and item you get.
• Compare every MSN or plan statement to your log as soon as it arrives.
• Call the provider first about a charge you do not understand; ask for an itemized statement if needed.
• Hang up on unexpected callers who ask for your Medicare Number, and call 1-800-MEDICARE yourself.
• Say no to "free" equipment in exchange for your number.
• Report suspected fraud to 1-800-MEDICARE or 1-800-HHS-TIPS, with your MSN in hand.
• Save the Senior Medicare Patrol number, 1-877-808-2468, for help.

A few minutes with each statement keeps your own record clean and, as CMS puts it, makes you the first line of defense against Medicare fraud and abuse.