Reading your Medicare Summary Notice line by line

What each column on the quarterly Medicare Summary Notice means, how to spot errors and fraud, and what Medigap pays afterward.

Every three months, people with Original Medicare get a Medicare Summary Notice (MSN) listing services billed to Medicare. It is not a bill.

Key columns

• Service provided and billing code.
• Amount the provider charged.
• Medicare-approved amount, which is what Medicare allows.
• Amount Medicare paid, usually 80% of the approved amount after the deductible.
• Maximum you may be billed: your share, which Medigap usually pays.

Check for errors

Compare dates and services with your own records. Watch for services you never got, duplicate charges or equipment you didn't order. These may be billing errors or fraud; see how to spot Medicare scams.

How Medigap fits

Most Medigap claims are crossed over automatically. If you have Plan G, your share after the Part B deductible is usually $0. See the plan letters at Medigap plans explained.

Online access

Create a Medicare.gov account to see claims within about 24 hours of processing and download electronic MSNs.

Questions people ask

Is the Medicare Summary Notice a bill?

No. It shows what was billed and what Medicare paid.

How often does the MSN come?

Every three months, if you had services.

What should I do about an error?

Call the provider first, then 1-800-MEDICARE if unresolved.

Does Medigap pay automatically?

Usually, through automatic crossover.

Independent educational site. Not affiliated with or endorsed by the U.S. government, the federal Medicare program, or any insurance company. Figures are 2026 amounts published by CMS unless noted; check Medicare.gov for your situation.