Glossary · Process & admin

ABN: the Advance Beneficiary Notice of Noncoverage

Whether you can bill a Medicare patient for a denied service often comes down to one form signed before the visit — the ABN.

An Advance Beneficiary Notice of Noncoverage (ABN) is a notice given to a Medicare fee-for-service patient before a service Medicare may not cover, transferring potential financial responsibility to the patient. Without a valid, properly executed ABN, a provider generally cannot bill the patient for a denied non-covered service.

When an ABN is required

  • Before a service the provider believes Medicare may deny as not reasonable and necessary.
  • It must be given in advance, with the reason and an estimated cost, and signed by the patient.
  • It applies to Medicare fee-for-service — not a general concept for all payers.

What it does

A valid ABN lets the provider bill the patient if Medicare denies the service. Without one (where required), the denial typically becomes a provider write-off rather than patient responsibility. It is not a way to bill the patient for genuinely covered services.

Frequently asked

Does an ABN guarantee I can bill the patient?
Only if it's valid and properly executed in advance, for a service Medicare denies as not reasonable and necessary. An invalid or late ABN generally can't shift the cost.
Do commercial payers use ABNs?
The ABN is a Medicare fee-for-service instrument. Commercial plans have their own notice and consent rules.

Primary sources: CMS — Beneficiary Notices Initiative (ABN). General information, not legal or medical advice — confirm against the governing rule for the plan type.

Related guides

CO-50 · Medical necessityPR-1 · Deductible (patient responsibility)Medical necessity

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