Medicare Summary Notice (MSN)
Updated September 30, 2026
Definition
A notice people with Original Medicare get every 6 months if they had care. It lists what providers billed, what Medicare paid, and what you may owe. It isn't a bill.
A Medicare Summary Notice (MSN) is a statement for people with Original Medicare. It lists the Part A and Part B services that providers billed to Medicare, what Medicare paid, and what you may owe. It isn't a bill. You get one in the mail every 6 months if you had care, or by email if you choose electronic MSNs.
For example, say a provider charges $250 and Medicare approves $100. After your deductible, Medicare pays $80 and your 20% share is $20. Compare the bill from that provider with the $20 on your MSN before you pay.
If you disagree with a decision, the last page of the MSN explains how and when to appeal. Our guide to reading a Medicare Summary Notice shows where each number is.
Related terms
Guides that use this term
- GuideHow to read a Medicare Summary NoticeYour Medicare Summary Notice isn't a bill. Learn what each column means, how to check it against your provider's bill, and how to appeal by the deadline.
- GuideMedical bill vs. EOB: how to compare them line by lineYour bill and your EOB should tell the same story. Here's how to compare them in 20 minutes, with a worked example and what to do if they don't match.
- Start hereHow to read a medical bill (and check it against your EOB)Learn each part of a medical bill and your EOB, what billing codes mean, and why 1 visit brings several bills. Then check what you owe before you pay.
Sources
- Medicare Summary Notice (MSN), Medicare.gov. Accessed September 30, 2026.
- Outpatient hospital services, Medicare.gov. Accessed September 30, 2026.
This is general information, not legal or medical advice. Rules can depend on your plan and your state. Romi Care isn't an insurer, law firm, collection agency, or government program.