Reviewed August 1, 2026

Medicare Summary Notice (MSN)

The statement Medicare sends to people with Original Medicare showing processed Part A and Part B claims, coverage decisions, payments, and the maximum amount the person may owe.

Plain-language definition

An MSN is an official claim summary, not a bill. It helps a person with Original Medicare compare services and supplies billed to Medicare with personal records and provider bills.

What appears on it

  • Services or supplies billed during the statement period.
  • Whether Medicare approved each claim and what Medicare paid.
  • The maximum amount the provider or supplier may bill the person.
  • Instructions for questions, corrections, suspected fraud, and appeals.

Paper and electronic notices

Medicare sends a paper MSN every six months when Original Medicare services or supplies were billed during that period. A person who chooses electronic delivery receives an email link for any month with a processed claim and can access the notice through a secure Medicare account.

Difference from an Explanation of Benefits

The MSN belongs to Original Medicare. Medicare Advantage, Medicare drug, and other Medicare health plans generally issue an Explanation of Benefits (EOB). A plan's EOB follows that plan's claim and appeal system.

Practical example

A Part B MSN may show an office visit, the provider's charge, Medicare's approved amount, Medicare's payment, and the maximum the person may owe. The person should compare it with the provider bill and any Medigap or other insurance statement before deciding what remains unpaid.

Official source

Medicare — Medicare Summary Notice

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