How to Fill Out the ABN Form for Medicare (CMS-R-131)

Form CMS-R-131, the Advance Beneficiary Notice of Noncoverage, is filled out by the healthcare provider before an Original Medicare beneficiary receives an item or service that Medicare is expected to deny. To complete the ABN form for Medicare correctly, the provider enters the patient’s name, lists each item or service with a specific reason Medicare is likely to deny it, gives a good-faith cost estimate for each, and then hands the form to the beneficiary, who selects one of three option boxes and signs and dates it before the service is delivered.¹ Every field has rules, and skipping one can make the whole notice unenforceable.

Before You Start: Confirm the Form Applies

The ABN is only for people enrolled in Original Medicare (Parts A and B, fee-for-service). Medicare Advantage plans use different notices: the Integrated Denial Notice (Form CMS-10003-NDMCP) for denials of coverage or payment, and the Notice of Medicare Non-Coverage (Form CMS-10123-NOMNC) for terminations of skilled nursing facility or home health services.² Hospitals and skilled nursing facilities use the ABN only for Part B items; Part A inpatient noncoverage uses the Hospital-Issued Notice of Noncoverage (HINN) instead.³

An ABN is required when Medicare ordinarily covers the service but the provider expects a denial for a specific reason, most commonly a medical-necessity judgment or a frequency limit (a screening or lab already used up for the covered interval).⁴ For services Medicare never covers, a voluntary ABN can be used as a courtesy; when it is voluntary, the beneficiary does not need to check an option box or sign.³

The current form, in English, Spanish, and large-print editions, is downloadable as a ZIP file from the CMS FFS ABN page.¹ You may reproduce it or integrate it into an electronic health record, but the wording of the three option boxes and required fields cannot be altered.

Filling In the Header: Patient Information

Enter the beneficiary’s full name exactly as it appears on their Medicare records. A minor misspelling or a missing middle initial will not invalidate the form as long as the patient recognizes the name.³ You may add an internal identification or medical record number to link the notice to the claim, and leaving that number blank does not invalidate the form. Do not put the Medicare Beneficiary Identifier or Social Security number anywhere on the ABN.⁴

Listing Items or Services and the Reason for Expected Denial

In the form’s table, list each item or service that Medicare is expected not to cover. Next to each entry, write a plain-language reason for the expected denial. Every listed item must have at least one corresponding reason, or the ABN is invalid.³

Vague language will not do. “May not be covered” is not a reason. A valid entry explains specifically why Medicare is likely to deny, for example: “Medicare limits this test to once every 24 months and your last test was 6 months ago.” The reason should give the patient enough detail to understand the denial risk they are accepting.

Entering the Cost Estimate

Each listed item needs a good-faith cost estimate. CMS expects the estimate to land within $100 or 25 percent of the actual cost, whichever amount is greater.⁴ Estimating a bit high is generally acceptable, since a lower final bill does not harm the patient.³ A cost range is fine. What you cannot do is leave the column blank or write “unknown”; without a number the patient cannot make an informed financial decision, and the notice fails.

The Three Option Boxes

Once the patient information, items, reasons, and cost estimates are filled in, the beneficiary reads the completed form and picks one of three options. The choice determines whether Medicare gets billed at all and whether the patient keeps the right to appeal.³

Option 1: Receive the item or service and have the provider submit a claim to Medicare. If Medicare denies, the patient gets a Medicare Summary Notice and can appeal. If Medicare pays, the provider refunds what the patient already paid, minus any copay or deductible. This option also allows a secondary insurer to be billed after Medicare processes the claim.
Option 2: Receive the item or service and pay out of pocket. No claim goes to Medicare and there are no appeal rights.
Option 3: Decline the item or service. Nothing is owed and there is nothing to appeal.

A provider cannot pre-select an option box. If any box is checked before the form reaches the patient, the entire ABN is invalid.³ The patient chooses without being steered. When there is doubt, Option 1 preserves the most rights, including the ability to have Medigap or employer coverage billed after Medicare’s formal decision.

Signature, Date, and Timing of Delivery

After choosing an option, the beneficiary signs and dates the form. The signature line cannot be filled in before the rest of the notice is complete; a signature collected on a blank or partially blank ABN voids the notice.³

CMS does not set a specific number of hours or days the ABN must be delivered in advance. The rule is that it must reach the beneficiary far enough before the service that they can read it, consider the options, and make an informed choice. Presenting the form to a patient already prepped for a procedure is exactly what the timing rule exists to prevent. ABNs are never required in emergencies; screening and stabilizing treatment cannot be delayed for paperwork.³

When the Patient Refuses to Sign or Cannot Sign

If the beneficiary wants the service but refuses to pick an option or sign, note the refusal directly on the ABN and list any witnesses present. CMS advises considering not delivering the service in that situation, unless withholding care would endanger the patient’s health or create civil liability.⁴

When the beneficiary cannot make their own healthcare decisions, an authorized representative signs on their behalf. An authorized representative is someone legally permitted to make health care and financial decisions for the beneficiary, such as a legal guardian or a person named in a durable medical power of attorney. If a known authorized representative exists, the ABN must be issued to that representative. The representative writes “rep” or “representative” next to the signature, and if the signature is not legible, prints the name on the form as well.

Mistakes That Make the ABN Invalid

An invalid ABN strips the provider of the right to collect payment from the patient for a denied service. Watch for these defects before delivering the notice:

A pre-selected option box, meaning any of Options 1, 2, or 3 was checked before the patient saw the form.³
A listed item with no corresponding reason for the expected denial.³
A blank or “unknown” cost estimate.
A signature collected before the notice was fully filled out.³
Delivery of the notice after the item or service was provided.

Some things that look like defects are not. A minor name misspelling is fine if the patient recognizes it, and the internal identification field can be left blank.³

After the Form Is Signed

Give the beneficiary a copy and keep the original. CMS requires providers to retain signed ABNs on file so the notice can be produced in a billing dispute or federal audit.³

When the claim goes to Medicare, attach the appropriate modifier. Only one of these modifiers may appear on a single claim line; they cannot be combined.⁵

GA: A signed ABN is on file, and the service is expected to be denied as not medically necessary. This is the standard modifier when a mandatory ABN was properly completed.⁶
GY: The item or service is statutorily excluded or falls outside any Medicare benefit definition, meaning Medicare never covers it.⁶
GZ: The service is expected to be denied as not reasonable and necessary, and no signed ABN was obtained. With GZ, the provider cannot collect payment from the patient for the denied service.⁶

1
Centers for Medicare & Medicaid Services. FFS ABN
2
Centers for Medicare & Medicaid Services. Notices and Forms
3
Centers for Medicare & Medicaid Services. Advance Beneficiary Notice of Non-coverage (ABN) Form Instructions
4
Centers for Medicare & Medicaid Services. Advance Beneficiary Notice of Non-coverage Tutorial
5
Noridian Healthcare Solutions. GA – JD DME
6
Centers for Medicare & Medicaid Services. Medicare Carriers Manual Part 3 – Claims Process