How often will I get a Medicare Summary Notice?

You typically receive an MSN every three months. It covers all services and supplies billed to Original Medicare during that period. If you haven't used any Medicare services recently, you might not get one in a particular quarter.

What if I don't agree with something on my MSN?

First, contact your doctor or supplier to clarify any charges or services you don't recognize. If you still believe there's an error, or if you suspect fraud, you have the right to appeal Medicare's decision. The MSN itself will have instructions on how to start an appeal process.

Does the MSN tell me how much my Medigap plan will pay?

No, the MSN only shows what Original Medicare paid and what you may owe. If you have a Medigap (Medicare Supplement) plan, it will send you its own Explanation of Benefits (EOB) detailing what it covered after Medicare processed the claim. You'll need to check your Medigap EOB for that information.

Why did my MSN say 'not covered' for a service I received?

Medicare may not cover certain services if they are not considered medically necessary, are experimental, or are excluded by law. If a service is denied, the MSN will explain why it wasn't covered. You have the right to appeal this decision if you believe it should have been covered.

Is the MSN the same as an Explanation of Benefits (EOB)?

They are very similar in purpose but come from different sources. The Medicare Summary Notice (MSN) comes from Original Medicare. An Explanation of Benefits (EOB) comes from other insurance plans, like a Medicare Advantage plan, a Medigap policy, or an employer-sponsored health plan. Both explain how your claims were processed.

Medicare Explained

What is the Medicare Summary Notice (MSN) and why is it important?

The Medicare Summary Notice (MSN) is a statement from Original Medicare that shows you what services and supplies were billed by your doctors and suppliers. It explains what Medicare paid, what you may owe, and helps you keep track of your healthcare claims. This notice is not a bill, but it's crucial for understanding your medical costs.

By the ExplainMyBill.ai Editorial Team · Reviewed by our billing research team

Published June 5, 2026 · Updated June 5, 2026

What is the Medicare Summary Notice (MSN)?

The Medicare Summary Notice, or MSN, is a statement that Original Medicare sends to you. It arrives in the mail every three months. Think of it as a detailed report of your healthcare visits and supplies. It lists everything your doctors and other providers billed to Medicare during that period.

This notice shows you what the provider charged, what Medicare decided to pay, and the amount you might be responsible for. It's only for people who have Original Medicare (Part A and Part B). If you have a Medicare Advantage Plan (Part C), you will get a different type of statement from your plan instead.

Why Does the MSN Matter?

Your MSN is a very important document, even though it's not a bill. It helps you keep track of all the medical services you've received. By reviewing it, you can make sure that Medicare was billed correctly for your care.

Checking your MSN helps you understand your healthcare costs and what Medicare is covering. It also allows you to spot any potential errors or even fraud. This way, you can protect yourself and Medicare from incorrect charges.

Key Information to Check on Your MSN

When you receive your Medicare Summary Notice, take a moment to look over these important details:

Your Name and Medicare Number: Make sure the information belongs to you.
Dates of Service: Check that these are the actual dates you received care.
Provider Information: Confirm the names of the doctors, hospitals, or suppliers who provided your services.
Services Received: Look at the descriptions of the care, tests, or supplies you got. Do they match your memory?
Amount Billed: This is what your provider charged for the service.
Approved Amount: This is the amount Medicare decided was appropriate to pay for the service.
Medicare Paid: This shows the portion that Original Medicare covered.
What You May Owe: This is your estimated share, which can include your deductible, copayments, or coinsurance. Remember, this is an estimate, not a bill.
Important Messages: Read any notes or messages carefully. They often explain why Medicare paid a certain amount or why a service was not covered.

Understanding Common MSN Confusions

It's easy to misunderstand some parts of the MSN. Here are a few common points of confusion:

It's Not a Bill: The most important thing to remember is that the MSN is NOT a bill. You will receive a separate bill directly from your doctor or supplier for any amounts you owe. Do not pay based on the MSN alone.

Estimated Costs: The 'What You May Owe' section is an estimate. Your actual bill might be different, especially if you have other insurance like a Medigap plan or employer coverage. Those plans will pay after Medicare.

Not for Medicare Advantage: If you have a Medicare Advantage Plan (Part C), you will not get an MSN. Your specific plan will send you its own statements detailing your claims and costs. These statements serve a similar purpose but come directly from your private insurance company.

Your Next Steps After Receiving an MSN

Once you get your Medicare Summary Notice, here's what you should do:

Review It Carefully: Compare the services listed against your own records or memory. Did you actually receive these services on these dates?

Keep It: File your MSN with your other important healthcare documents. It's a useful record of your care.

Contact Your Provider First: If you see something you don't recognize or have questions about a service, call your doctor's office or the supplier. They can often clarify billing issues or correct mistakes.

Contact Medicare: If you can't resolve an issue with your provider, or if you suspect fraud or abuse, contact Medicare directly. The MSN itself will have instructions on how to appeal a decision or report concerns.

Wait for a Bill: Remember, the MSN is not a bill. Wait until you receive a bill from your provider before making any payments.

Frequently asked questions

How often will I get a Medicare Summary Notice?: You typically receive an MSN every three months. It covers all services and supplies billed to Original Medicare during that period. If you haven't used any Medicare services recently, you might not get one in a particular quarter.
What if I don't agree with something on my MSN?: First, contact your doctor or supplier to clarify any charges or services you don't recognize. If you still believe there's an error, or if you suspect fraud, you have the right to appeal Medicare's decision. The MSN itself will have instructions on how to start an appeal process.
Does the MSN tell me how much my Medigap plan will pay?: No, the MSN only shows what Original Medicare paid and what you may owe. If you have a Medigap (Medicare Supplement) plan, it will send you its own Explanation of Benefits (EOB) detailing what it covered after Medicare processed the claim. You'll need to check your Medigap EOB for that information.
Why did my MSN say 'not covered' for a service I received?: Medicare may not cover certain services if they are not considered medically necessary, are experimental, or are excluded by law. If a service is denied, the MSN will explain why it wasn't covered. You have the right to appeal this decision if you believe it should have been covered.
Is the MSN the same as an Explanation of Benefits (EOB)?: They are very similar in purpose but come from different sources. The Medicare Summary Notice (MSN) comes from Original Medicare. An Explanation of Benefits (EOB) comes from other insurance plans, like a Medicare Advantage plan, a Medigap policy, or an employer-sponsored health plan. Both explain how your claims were processed.

This article is educational information, not medical, legal, or financial advice. Billing rules change and individual situations vary — always confirm details with your provider or insurer.