How to Read Your Medicare Summary Notice (MSN), Line by Line

The Medicare Summary Notice (MSN) is a statement people with Original Medicare get in the mail at least every 6 months when they've had Part A or Part B services. It lists every service a provider billed to Medicare, what Medicare approved and paid, and the most you can be billed for each one. The top of the notice says "THIS IS NOT A BILL," so don't send payment to Medicare from it; use it to check the bills your doctors and hospitals send you.

Who gets a Medicare Summary Notice, and how often does it come?

You get an MSN if you have Original Medicare (Part A, Part B, or both). Medicare mails it every 6 months if you had any services or supplies during that period. If you had no services, you won't get one.

You can also sign up for electronic MSNs. With those, Medicare emails you a link for any month you have a processed claim, so you don't have to wait months for the paper copy. Large-print and Braille versions are available on request.

If you're in a Medicare Advantage plan, you won't get an MSN for your medical care. Your plan sends its own statement, usually called an Explanation of Benefits.

There are separate MSNs for Part A (hospital, skilled nursing, hospice, home health) and Part B (doctors, outpatient care, tests). Medical equipment like walkers or oxygen can come on its own durable medical equipment (DME) notice.

What's on page 1 of the MSN?

Page 1 is a summary. On the official Medicare sample, it shows:

• Your name, address, and Medicare Number. Check the address. If it's wrong, call Social Security to change it.
• Date of this notice and the claims period. This tells you which months the notice covers.
• Your deductible status. It tells you how much of this year's Part B deductible you've already met.
• "Did Medicare approve all services?" A simple yes or no. If it says NO, at least one item was denied.
• "Number of services Medicare denied."
• "Total you may be billed." The combined most you can owe all providers on this notice.
• Providers with claims this period. A list of doctors, labs, and facilities that billed Medicare, with dates.

If the "Total you may be billed" number looks wrong next to the bills you've received, flag it right away.

What does each column in the claims table mean?

The later pages break down each claim. On a Part B MSN the columns are:

• Service provided & billing code. A short description, plus a 5-character code in parentheses. That code is usually a Current Procedural Terminology (CPT) or Healthcare Common Procedure Coding System (HCPCS) code, which you can match to your provider's itemized bill.
• Service approved? Yes or No.
• Amount provider charged. What the office billed. This number is often much higher than what Medicare approves or what you owe.
• Medicare-approved amount. The amount Medicare allows for that service. For providers who accept assignment, this is the full price for the service.
• Amount Medicare paid. Medicare's share, usually 80% of the approved amount after your deductible is met.
• Maximum you may be billed. Your share. This is the most the provider can bill you for that line, before any Medigap or other insurance pays.
• See notes below. Letters that point to explanations at the bottom of the page, such as why something was denied or whether the claim was sent to your supplement plan.

Medicare's own sample shows an eye exam where the provider charged $143.00, Medicare approved $107.97, Medicare paid $86.38, and the maximum the patient could be billed was $21.59. That $21.59 is the 20% coinsurance on the approved amount.

How do I check my MSN against my medical bills?

Lay the MSN next to the bills and receipts from the same months. Then go line by line:

1. Do you recognize every provider name? Hospital-based doctors such as radiologists and anesthesiologists often bill separately, so a name you don't know may still be legitimate. Look it up before you assume fraud.
2. Do the dates match visits you had?
3. Did you get each service listed? Look for tests, equipment, or visits you don't remember.
4. Does the bill match the "Maximum you may be billed" column? If the provider's bill asks for more, ask why.
5. If you already paid, did you pay the right amount? If you overpaid, ask the office for a refund.
6. Look for a note saying your claim was sent to your Medigap or other insurer. If so, wait for that plan to pay before you pay the provider.

Medicare's notice itself suggests these same checks under "How to Check This Notice."

What should I do if a service on my MSN was denied?

First, read the note letter next to the denied line. It gives a short reason, such as "the information provided does not support the need for this service."

Then call the provider's billing office. Ask whether they sent the right codes and diagnosis. Sometimes a denial comes from a coding mistake, and the office can fix it and resubmit.

If you still disagree, you can appeal. The last page of the MSN tells you how, and it gives a "We must receive your appeal by" date. The sample notice says the claims office must get your appeal within 120 days from the date you get the notice. To appeal:

• Circle the item you disagree with on a copy of the MSN.
• Write why you disagree, on the MSN or a separate sheet.
• Add your name, phone number, and Medicare Number.
• Include anything that helps, like a letter from your doctor.
• Mail it to the address listed on the last page, and keep copies.

Medicare's appeals page says you'll generally get a decision within 60 days after the contractor receives your appeal.

What if something on my MSN looks like fraud?

If you see a provider you never visited, equipment you never got, or a service on a day you were home, call the provider first to rule out a simple mix-up. If it still doesn't make sense, report it to 1-800-MEDICARE (1-800-633-4227). The MSN itself lists offers of free medical services and billing for services you didn't get as examples of fraud.

Where can I get free help reading my MSN?

Your State Health Insurance Assistance Program (SHIP) offers free, one-on-one Medicare counseling. Find your local SHIP at shiphelp.org. You can also call 1-800-MEDICARE.

Frequently asked questions

Is the Medicare Summary Notice a bill?

No. It says "THIS IS NOT A BILL" at the top. Any bill will come from your doctor, hospital, or supplier.

Why is the "amount provider charged" so much higher than what Medicare paid?

Providers list their standard charges, but Medicare sets an approved amount for each service. If your provider accepts assignment, the approved amount is the full payment, and you owe only your deductible and coinsurance.

How long should I keep my MSNs?

Keep each MSN at least until any bills and appeals for those services are settled. Many families keep them with the matching bills for the year.

Can I see my claims before the paper MSN arrives?

Yes. You can sign up for electronic MSNs or check your claims in your Medicare.gov account, which shows claims after they're processed.

What's the deadline to appeal something on my MSN?

Use the "We must receive your appeal by" date printed on the last page of your notice. Medicare's sample notice describes it as 120 days from the date you get the notice.

Want a second set of eyes on your MSN?

Bill Review Coach is a monthly medical bill review service for seniors and their families. Snap a photo of your MSN and the bills that go with it, and you'll get back a plain-English summary of anything that doesn't match, plus what to say when you call the billing office. You make the calls and write the emails; we help you know what to say.