ABN Documentation: What Medicare Requires From Your Practice

A valid ABN is the current CMS form, completed in full, explained to the patient and signed before the service, then tied to the encounter and kept in the record. If any of those pieces is missing, you can lose the right to bill the patient when Medicare denies the claim. This guide covers when an ABN is mandatory, how to complete each part, what to keep, and where practices get caught.

TL;DR

• Use only the current CMS-R-131 form, and only for Original Medicare fee-for-service patients, never for Medicare Advantage (Part C) or Part D.
• An ABN is mandatory when you expect Medicare to deny a usually covered service, for example for medical necessity or frequency limits. It is voluntary for services Medicare never covers.
• Deliver it before the service, explain it, get a signature and date, give the patient a copy, and keep the record.
• Be specific about the service, the reason for expected denial and the estimated cost. Vague wording is the most common weakness.

Table of Contents

• What an ABN does and does not do
• Which form to use in 2026
• When an ABN is mandatory and when it is voluntary
• How to complete the ABN, field by field
• The delivery sequence that holds up
• Retention and who keeps the ABN
• What an audit looks for
• Our perspective: ABN failures are workflow failures
• See where your claims are exposed
• A practical ABN checklist for your front desk
• FAQ
• Sources

What an ABN does and does not do

The Advance Beneficiary Notice of Noncoverage is a notice you give an Original Medicare patient when you expect Medicare to deny payment for something it usually covers. It lets the patient decide, with a real cost estimate in hand, whether to get the service and accept financial responsibility.

CMS frames it as a communication and liability process. The MLN tutorial on the ABN is built around the patient having enough information and time to choose before the service happens. So an ABN is not a fix you apply after a denial. A form signed after the visit protects no one.

The notice applies to physicians, practitioners, suppliers, independent laboratories, home health agencies and hospices in the applicable fee-for-service settings, according to CMS.

Which form to use in 2026

CMS lists Form CMS-R-131 as the current ABN. According to CMS's FFS ABN page, the updated form expires March 31, 2029, and providers had to move off the expired version by May 12, 2026.

If your front desk still prints a saved copy from a few years ago, check it first. Pull the current form and instructions from CMS, replace every template (paper, EHR and patient portal), and remove the old file so no one reuses it. CMS's Medicare Claims Processing Manual update says that failing to use the mandated notice can lead to the notice being invalidated.

When an ABN is mandatory and when it is voluntary

The trigger is not "patient might owe money." The trigger is a specific expected denial of a service Medicare usually covers.

Mandatory situations

Per the Medicare Claims Processing Manual, Chapter 30, an ABN is required before furnishing an item or service that is usually covered when you expect denial because it is:

• Not reasonable and necessary for this patient (frequency limits and diagnosis mismatches are common examples)
• Experimental or investigational
• Custodial care
• Subject to another limitation-on-liability circumstance CMS lists

The same manual warns that failing to issue a required notice, or issuing a defective one, can leave the provider financially liable and may expose it to sanctions.

Voluntary situations

An ABN is not required just because a service is never a Medicare benefit or is statutorily excluded. CMS's ABN FAQ describes that use as voluntary. You may still give a voluntary ABN or another notice as a courtesy, but the mandatory completion rules do not apply the same way.

The practical point: do not turn the ABN into a universal self-pay form. Coverage status and the reason for the expected denial should drive the workflow. A practice that hands an ABN to everyone dilutes the notice and teaches staff to stop reading the reason.

Not for Medicare Advantage or Part D

The biggest payer error is using the FFS ABN for the wrong plan. CMS says plainly on its FFS ABN page that the form is not for Part C or Part D. Medicare Advantage plans have their own denial and appeal notice processes. Build a payer check into registration so staff confirm the plan type before any ABN is prepared.

How to complete the ABN, field by field

CMS's form instructions set out what a valid notice needs. Use the latest OMB-approved one-page form, complete every applicable field, and obtain the patient's or representative's signature and date before the service.

Write the reason like a clinician would defend it

The form's plain-language design does not remove the need for clinical specificity. CMS's instructions call for the notice to say why Medicare may deny the service. A defensible entry connects three things: the service, the reason this patient's care is likely to be denied, and the cost. "Medicare does not cover this test more often than once in the allowed interval, and our records show your last one was on [date]" is useful. "May not be covered" is not.

This matters because the reason on the ABN should agree with your chart. If the ABN says the service fails medical necessity, but your note describes a clear necessity, you have an inconsistency that a reviewer can use. Our guide to medical necessity documentation examples shows how the clinical record should read, and this walkthrough of Medicare medical necessity denials covers how to catch problems before the claim goes out.

Estimated cost: be honest and be specific

A common failure is a vague or missing estimate. CMS requires a good-faith estimated cost, and the patient must understand the choices before picking an option. Keep a short internal fee list for services that commonly trigger ABNs, so staff quote the same figure every time and the estimate is traceable to your fee schedule.

The delivery sequence that holds up

CMS's manual update on Section 50 describes delivery that is in person when possible, early enough for meaningful consideration, explained fully, understood and signed. A workable sequence:

1. Identify the likely noncoverage event. This happens at scheduling, at check-in or when a clinician places an order.
2. Confirm Original Medicare. Not Medicare Advantage, not Part D.
3. Prepare the current CMS-R-131 with the specific service, reason and estimate.
4. Deliver before care, not in the exam room with the patient already undressed or waiting for the procedure.
5. Explain it in full and answer questions.
6. Let the patient choose Option 1, 2 or 3.
7. Obtain signature and date, from the patient or representative.
8. Give the patient a copy.
9. Retain the signed record in the medical record and link it to the order and claim.

If the patient refuses to sign or choose

CMS instructs the notifier to annotate the original notice, give the patient a copy and retain the annotated notice. The same guidance says the practice should consider not furnishing the service, unless health, safety or liability considerations make that impracticable. Do not pressure the patient. Document what was explained and what the patient said.

How long a signed ABN stays valid

Do not treat a signed ABN as reusable forever. Per the MLN tutorial, it remains effective only while the described care, the patient's relevant health status and Medicare coverage rules stay unchanged. For repetitive or continuous care, CMS permits another ABN after one year, and a material change requires a new notice sooner. Put a review date on recurring-care patients.

Retention and who keeps the ABN

CMS's general guidance, in the same manual update, is five years from discharge or completion of delivery of care when no other applicable requirement controls. Electronic retention is acceptable. A scanned copy works for the electronic record, but preserve the original or a reliable copy of any annotated notice.

If you order a service that someone else bills, such as laboratory, pathology or imaging, and you are not the Medicare billing entity, CMS says to send the signed ABN to the billing laboratory or other billing entity. Set up a standing handoff so the billing entity receives the ABN with the order, not after a denial. Practices that move to paperless storage can also look at general guidance on managing records and documentation for medical supplies and equipment when they sort out how procurement paperwork and billing records sit together.

What an audit looks for

The manual places the evidentiary burden on the notifier when a notice's validity is challenged. That means "we gave one" is not enough. An audit-ready file links:

• The encounter and the order
• The medical-necessity rationale
• The cost estimate and its source
• The signature, date and delivery method
• The claim it supports

The signature itself needs care. If your practice uses electronic signatures on documents, review four controls for physician e-signature compliance, and for late-signed clinical notes see our piece on signature attestations. Those cover clinician signatures, not the patient's ABN signature, but the same discipline applies: a signature you can't tie to a person, a date and a document is weak evidence.

If a payer later asks you to return money, a clean ABN file is part of your response. See how to respond to an overpayment demand.

Our perspective: ABN failures are workflow failures

We look at practice data every day, and ABN problems rarely come from the form. They come from the handoffs around it. The order is placed in the EHR, the patient is already in the lab chair, and no one asked whether the plan is Original Medicare. Or the ABN was signed months ago and reused for a changed course of care.

The fix is not another policy memo. It is a short list of services that trigger ABNs at your practice, a payer check at registration, and a way to see which claims went out with a notice and which should have. That last part is where practices leave money on the table: services written off to the patient's account that could not be billed, or denials absorbed because the notice was defective.

We treat ABN documentation as one piece of claim-level compliance. When we audit charts we look at whether the documentation, the coding and the notice tell the same story, because a reviewer will compare them.

— Elena

See where your claims are exposed

If you want to know how often missing notices, thin documentation and charge-capture gaps cost your practice, our free 30-day Revenue Leakage Audit scans your EHR data and quantifies the gaps per provider and per payer, with no new staff or software training required. You can also learn more about our HIM compliance engagement.

A practical ABN checklist for your front desk

• Current CMS-R-131 loaded; old versions deleted
• Payer check: Original Medicare only
• List of services that commonly trigger an ABN, with fee estimates
• Specific service and reason written on every notice
• Delivered before care, explained, patient chooses an option
• Signature and date from patient or representative
• Copy to the patient; record in the chart
• Signed copy sent to the billing entity when it isn't you
• Review date for recurring care, no later than one year
• Monthly spot check of ten notices against claims

For related documentation habits that reduce denials, see our 99214 documentation checklist.

FAQ

Is an ABN only for Medicare patients?

Yes. The CMS-R-131 is for Original Medicare fee-for-service beneficiaries. CMS says not to use it for Medicare Advantage (Part C) or Part D. Commercial plans have their own notice and waiver rules, so check each contract.

Where can I find the current ABN form?

CMS publishes it on its FFS ABN page, along with the instructions. Download the current version from there rather than copying one from an old file or a third-party site.

Do I need an ABN for a service Medicare never covers?

Not as a mandatory step. CMS describes ABNs for statutorily excluded services as voluntary. You can still give a courtesy notice, but be clear with the patient about what it is.

Can I keep ABNs electronically?

Yes. CMS accepts electronic retention, and a scanned copy is acceptable for the electronic medical record. Preserve the original or a reliable copy of an annotated notice, and keep it for the general five-year period unless another requirement controls.

Sources

• CMS: FFS ABN (Form CMS-R-131)
• CMS: Medicare Claims Processing Manual, Chapter 30, Section 50
• CMS: ABN and Therapy Caps FAQs
• CMS: ABN Form Instructions
• CMS: Section 50, Chapter 30 manual updates
• CMS MLN: ABN Tutorial

Recommended

• Stop Medicare Medical Necessity Denials: 30 Day Audit for US Practices
• Stop 99214 Denials: 9 Point Documentation Checklist for US Practices
• Chronic Care Management Documentation: Five Records Medicare Requires
• Why Documentation Affects Reimbursement in Physician Practices