Who sends it: Medicare, about every 6 months, if you have Original Medicare and used services in that time.
What this notice is
The Medicare Summary Notice, or MSN, comes from Medicare itself. You get it if you have Original Medicare (Part A, Part B or both) and a doctor, hospital, lab or supplier sent Medicare a claim for you. If no claims came in during that time, no notice is mailed.
Medicare's website now says it mails the MSN every 6 months when you had services in that period. Older guides may say every 3 or 4 months, because the schedule has changed over the years.
Near the top it says it is not a bill. If you have a Medicare Advantage plan instead, you get an Explanation of Benefits from your plan, not an MSN.
What to check, line by line
- Each provider name. Did you really see this doctor, lab or supplier?
- Each date of service. Were you there that day?
- Each service or item. A brace, test, scan or wheelchair you never got is a warning sign.
- Service approved: Yes or No. A No means Medicare did not pay that item.
- Maximum you may be billed. If a bill from that provider asks for more than this, call the provider and ask why.
What to do if something looks wrong
- Call the provider's office first. It may be a simple mistake, like a wrong date or code.
- If you do not recognize the provider or the service at all, call 1-800-MEDICARE (1-800-633-4227) and report it. Someone may be using your Medicare number.
- Keep your receipts and calendar notes so you can compare them with the next notice.
How to appeal a denied claim
The last page of the MSN explains how to appeal and gives the deadline. For Original Medicare you generally have 120 days from the date you get the notice to ask for this first appeal, called a redetermination.
The notice tells you to circle the items you disagree with, write why, sign it, and mail it to the address shown, keeping a copy. A note from your doctor explaining why you needed the service helps. A free SHIP counselor can walk you through it. Find one at shiphelp.org.
How to tell a real one from a fake
A real MSN comes in the mail from Medicare, or by email if you chose electronic notices. You can see the same claims by signing in at medicare.gov. A real MSN never asks you to pay Medicare, call to verify your Medicare number, or give card details.
If someone calls about your summary notice and asks for your Medicare number, hang up. Medicare already has it. You can also choose electronic MSNs at medicare.gov: you get an email with a link for any month a claim is processed, and the paper notice stops.
Have one in front of you?
Take a clear photo and text it to Uncle at +1 208 214 0093. He tells you in plain words what it says, what it wants from you, and anything that looks wrong. How to take a clear photo.
This page explains what this kind of letter usually means. Your letter is the final word on your dates and amounts. For a decision about taxes, health coverage or a legal matter, call the office that sent it, using the number on its official website, or ask a professional you trust.
Read next
- Explanation of Benefits (EOB)
- Advance Beneficiary Notice (ABN)
- Medicare scam
- Protect your Medicare number
- See all letters explained
Written by the Textuncle team. Last updated October 3, 2026.
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