Advance Beneficiary Notice (ABN): what it means and what to do

Warns in advance that Original Medicare may not pay for a specific item or service. Informational on its own — the document that decides who's liable once matched against an actual denied service on the MSN.

An Advance Beneficiary Notice is informational on its own — it isn't a denial and doesn't start any appeal clock. It only matters once matched against an actual denied service on your Medicare Summary Notice.

Without a valid ABN given before the service, the provider — not you — is generally the one considered to have known Medicare might not pay, and generally can't collect from you.

This is where most family cases involving a provider bill are actually won or lost — not by arguing the underlying medical necessity question, but by showing no valid ABN was ever given.

A valid ABN also isn't permanent — for an ongoing course of treatment, the provider generally has to give a fresh one at least once a year. A notice signed long before the actual dates of service being billed doesn't protect the provider's right to collect.

Keep the signed copy, not just a memory of signing something — if a bill shows up later, the ABN's own date, and exactly which service it names, are the two facts that decide whether you owe anything at all.

Read what it actually says. An ABN (form CMS-R-131) warns you in advance that Medicare may not pay for a specific item or service, and gives you the choice to get it anyway and pay yourself if Medicare doesn't.

Keep it — it decides liability later. If the service is later denied on your MSN, this document (or its absence) decides whether you're actually responsible for the bill.

Check whether it names this exact service. A blanket ABN covering "whatever Medicare doesn't pay" is different from one that specifically names the service you got — that difference can matter.

Check whether it was filled out properly. A pre-checked option, no real cost estimate, or being asked to sign during an emergency can each make an ABN invalid.