Advance Beneficiary Notice (ABN)
An Advance Beneficiary Notice of Noncoverage (ABN) is a standardized CMS notice a provider or supplier gives a Medicare fee-for-service beneficiary before furnishing an item or service that Medicare is expected to deny, so the beneficiary can decide whether to accept financial responsibility.
Updated
The Advance Beneficiary Notice of Noncoverage, commonly shortened to ABN, is a written notice issued under Original (fee-for-service) Medicare Part A and Part B. Providers, physicians, practitioners, and suppliers use the CMS-standardized form to tell a beneficiary, in advance, that Medicare probably will not pay for a specific item or service and to explain why. The purpose is to give the beneficiary an informed choice about whether to receive the item or service and accept potential out-of-pocket liability.
An ABN is generally used when a service may be denied because Medicare does not consider it reasonable and necessary in the particular situation, or for certain other coverage limitations. The notice identifies the item or service, states the reason payment is expected to be denied, and offers the beneficiary options for how to proceed. When a valid ABN is properly delivered and signed, it can shift financial responsibility to the beneficiary if Medicare later denies the claim. The specific form, its required fields, and the rules for when notice is mandatory versus voluntary are set by CMS and can change over time, so the current official form and instructions should be confirmed at the CMS source.
The ABN is distinct from claim coding itself; it interacts with billing through specific modifiers appended to the claim to indicate that a notice was or was not on file. Because the exact modifiers, thresholds, and delivery requirements are governed by CMS manuals and guidance and may be updated, providers rely on current CMS instructions rather than fixed figures or deadlines.
In practice
In a billing workflow, an ABN is prepared and delivered before the item or service is furnished, giving the beneficiary time to read the notice, ask questions, and select an option before signing. Front-desk, clinical, and billing staff typically coordinate so the correct item or service and reason for expected denial are described in plain language on the current CMS form. Once signed, the notice is retained, and the claim is submitted with the applicable Medicare modifier to signal that an ABN is on file. The precise modifier and its meaning depend on CMS coding guidance in effect at the time of billing.
ABNs apply to Original Medicare rather than to Medicare Advantage (Part C) plans, which use their own coverage and notice rules. Whether a notice is mandatory or voluntary, and the circumstances that trigger it, are defined by CMS; because these requirements and the form itself are periodically revised, billing teams verify the active version and instructions against the authoritative CMS source rather than assuming a fixed rule.
Commonly confused with
- Medicare Advantage denial notices: The ABN is a tool of Original (fee-for-service) Medicare. Medicare Advantage (Part C) plans use their own coverage determination and denial notice processes, not the ABN, so the two should not be conflated.
- Hospital Issued Notice of Noncoverage / inpatient notices: The ABN generally addresses outpatient and Part B items and services expected to be denied as not reasonable and necessary; hospitals use separate CMS notices for inpatient and hospital-specific noncoverage situations.
- Explanation of Benefits (EOB) / Medicare Summary Notice: An ABN is issued in advance to warn of an expected denial before service; an EOB or Medicare Summary Notice is issued after a claim is processed to report what Medicare actually paid or denied.