I have Medicare Advantage — why don't I get an MSN?

Medicare Advantage plans handle your claims instead of Original Medicare. Since your plan processes the claims directly, your plan sends you an Explanation of Benefits (EOB) instead. You will only receive MSNs if you switch back to Original Medicare.

Is an EOB or MSN a bill?

No. Neither document is a bill. They are informational statements showing what was billed, what was covered, and what you may owe. Always wait for an actual bill from your provider before making any payment.

I have Original Medicare and Medigap — do I get both?

Yes. You receive an MSN from Medicare summarizing your Part A and Part B claims, and you may also receive an EOB from your Medigap insurer showing what they covered after Medicare paid its share.

How long should I keep these statements?

Keep EOBs and MSNs for at least one year, or until you have verified all charges are correct and any disputes have been resolved. Some advisors recommend keeping them for up to three years for tax and records purposes.

What if I see a charge for a service I never received?

Report it immediately. This could indicate a billing error or potential fraud. For EOBs, contact your insurance company. For MSNs, call 1-800-MEDICARE (1-800-633-4227). You can also report suspected fraud to the HHS Office of Inspector General.

EOB vs MSN: What's the Difference?

If you have Medicare, you probably receive statements about your healthcare claims — but they may come from different sources and look quite different. Understanding the difference between an Explanation of Benefits (EOB) and a Medicare Summary Notice (MSN) helps you track your costs and catch errors.

Neither an EOB nor an MSN is a bill. Don't pay anything until you receive an actual bill from your provider.

Quick distinction:

EOB = from your private insurer (Medicare Advantage, Medigap, employer plan)
MSN = from the federal Medicare program (Original Medicare Part A/B)

What Is an Explanation of Benefits (EOB)?

An Explanation of Benefits is a statement from your private health insurance company — not a bill. It shows:

The service you received and the date
The amount your provider charged
The amount your plan approved and paid
Any discount applied through network agreements
Your share: deductible, copay, or coinsurance owed

You receive EOBs if you have Medicare Advantage, Medigap, employer coverage, or individual insurance. Most insurers send them after each claim is processed, and many offer online portals or mobile apps for easy access.

What Is a Medicare Summary Notice (MSN)?

A Medicare Summary Notice is a quarterly statement from the federal Medicare program covering all Part A and Part B claims during a three-month period. It includes:

Services you received and providers who treated you
Amounts Medicare approved and paid
Your deductible and coinsurance responsibility
Notes if a claim was denied and why

You receive MSNs if you have Original Medicare (Part A and/or Part B) without Medicare Advantage. They are standardized by CMS and sent quarterly.

Key Differences Between EOB and MSN

Feature	EOB	MSN
Sent by	Private insurer	Federal Medicare program
Covers	Claims processed by your private plan	Part A and Part B claims under Original Medicare
Frequency	After each claim is processed	Quarterly (every 3 months)
Who gets it	Medicare Advantage, Medigap holders	Original Medicare beneficiaries
Format	Varies by insurer	Standardized by CMS

When Do You Get Each Statement?

You receive EOBs if you have Medicare Advantage, Medigap, employer coverage, or individual insurance. They typically arrive after each claim is processed.

You receive MSNs if you have Original Medicare (Part A and/or Part B) without Medicare Advantage. They arrive quarterly, covering all claims from the previous three months.

What to Do If You See an Error

Review every EOB and MSN when it arrives. If you find an error on an EOB, contact your insurance company. If you find an error on an MSN, call 1-800-MEDICARE (1-800-633-4227).

Red flags to watch for:

Services listed that you didn't receive
Dates that don't match your appointments
Duplicate charges for the same service
Provider names you don't recognize

Errors can indicate simple billing mistakes, but they can also be signs of Medicare fraud. Reporting them promptly protects both you and the Medicare program.

How to Access Your Statements Online

MSNs: Log into Medicare.gov with your account to view and download your Medicare Summary Notices.

EOBs: Most insurers offer online portals or mobile apps where you can view your Explanation of Benefits statements. Check your insurer's website or call member services for access.