An advance beneficiary notice of noncoverage (ABN), form CMS-r-131, sometimes called a waiver of liability is a standardized written notice that providers and suppliers of healthcare Services must deliver to Medicare fee-for-service beneficiaries prior to furnishing Services or items that Medicare is very unlikely to cover in that specific circumstance. The purpose of an ABN is to allocate the financial burden of service denial to the beneficiary. In cases where you fail to furnish a proper ABN when required, you may not bill the patient for the service; you incur full financial loss. If you improperly Complete an ABN, the ABN will be considered as if no ABN was furnished. Therefore, it is essential that the completion of the ABN is done accurately. This guide describes the 2026 updates made to the ABN, including when and how to utilize the ABN form, and what documentation is needed to safeguard your financial interests.
What Is an Advance Beneficiary Notice (ABN)?
A formal notice issued by a provider to a Medicare beneficiary, informing the beneficiary that Medicare is likely to deny payment for a specific service. Even though Medicare typically covers a service in other instances, an ABN is required to inform the patient that Medicare will probably deny payment for that specific service. When the patient signs the ABN, the patient assumes the responsibility for paying for the service if Medicare denies the claim.
The ABN applies only to Original Medicare (parts a and b) beneficiaries. The ABN may not be used for a Medicare advantage (part c) program or a part d prescription drug program. Skilled nursing facilities use the ABN only for items and services expected to be denied under Medicare Part B.
The form performs two key functions.
First, it provides the patient with informed consent. Patients are able to determine if they wish to receive a service knowing that they could be responsible for paying out-of-pocket for it.
Second, it protects the provider. The provider may bill the patient directly when Medicare denies the claim, since the provider has provided a valid ABN. However, without a valid ABN, the provider will lose money on denied claims.
When must an ABN be provided?
You must provide an ABN whenever you reasonably expect Medicare will deny payment for an item or service that Medicare normally covers. Your obligation to provide an ABN is established based upon your knowledge or reasonable expectation that the service will not be paid for by Medicare in this instance.
The most common scenarios that establish the obligation to provide an ABN include:
Coverage Rules Under LCDs and NCDs
The expectation that Medicare will deny a claim is not a guess. It comes from coverage rules published as National Coverage Determinations, which apply nationwide, and Local Coverage Determinations, which are issued by your Medicare Administrative Contractor for your jurisdiction. These documents define the diagnoses, frequencies, and clinical conditions under which Medicare pays for a service. When a physician orders a test for a diagnosis outside the covered list, or sooner than the covered interval allows, the coverage determination is the reasonable basis for issuing an ABN. Laboratories deal with this constantly, since a large share of all ABNs are triggered by a mismatch between the ordering diagnosis and the diagnoses a lab test’s coverage policy allows.
Lack of medical Necessity
You reasonably expect that the service requested by the patient is not medically necessary. This does not indicate you believe the patient does not require care. It merely indicates you realize that Medicare’s coverage standards will not be satisfied.
Excessive Frequency
The patient seeks a service more frequently than allowed by Medicare for that diagnosis. For example, a patient wishes to have a diagnostic test performed more than the maximum number of times permitted during a calendar year by Medicare.
Custodial Care
The patient requires custodial care that does not satisfy Medicare’s definition of skilled care.
Other types of situations that necessitate an ABN include:
DMEPOS Situations
Services that have been removed from or discontinued by Medicare;Two additional triggers apply specifically to durable medical equipment suppliers: items ordered as a result of prohibited unsolicited telephone contact, and items furnished by a supplier that has not obtained a required supplier number. Suppliers should also issue an ABN when equipment is replaced sooner than Medicare’s replacement timeframe allows.
Prior to providing the service to the patient, an ABN must be furnished to the patient. Providing an ABN at the time of service or after providing service is insufficient.
When should an ABN not be used?
Do not use an ABN for Services that Medicare will always exclude from reimbursement as they are statutorily excluded. Examples of such Services include routine physical examinations, cosmetic surgery, and hearing aids. Regardless of circumstances, Medicare will never pay for these Services.
Although an ABN is not necessary for these Services, CMS recommends that you use a voluntary ABN or similar notice as a courtesy to notify your patients about their possible financial responsibility. Using such a notification helps create goodwill and ensures your patients are aware of their possible financial responsibilities prior to making decisions regarding out-of-pocket payments.
Do not use an ABN for every service furnished to Medicare patients. You are prohibited from utilizing an ABN on a “routine basis” where there is no reasonable basis for Medicare to refuse coverage. Issuing an ABN to every Medicare patient regardless of circumstances, will result in a red flag being raised by auditors.
Emergencies and Duress
Never issue an ABN during an emergency or in circumstances where the patient cannot make an unpressured decision. A notice handed to a patient on a gurney, or presented moments before a procedure begins, is invalid because the patient had no genuine opportunity to weigh the choice. CMS treats notices delivered under duress as if no notice was given, which means the liability stays with the provider. If the situation is emergent, furnish the care and address coverage afterward.
The 2026 ABN Form Update: What Changed
On March 13, 2026, the Office of Management and Budget approved an updated version of the Advance Beneficiary Notice of Noncoverage (ABN), form CMS-r-131. The revised form became effective immediately and is valid through March 31, 2029.
In addition to the new form becoming effective on March 13, 2026, providers may continue to use the prior version of the ABN through May 12, 2026. On May 12, 2026, providers must begin exclusively using the revised version of the ABN. Failure to switch over will prohibit providers from passing on their financial liability to Medicare patients when claims are denied.
Changes in the revised version of the form
CMS states that they framed their revisions primarily as improvements to usability rather than changes in policy.
- Revisions in plain language: CMS re-wrote portions of the notice using simpler language intended to improve beneficiaries’ understanding of their rights and possible liability.
- Changes in simplified table structure: The “Medicare Exclusions & Cost Table” utilizes simplified column headings allowing easier recognition of Services and bases for non-payment.
- Reduction of duplicate references: prior versions included references to “the care described above (d)” which created opportunities for errors when referencing care multiple times throughout the notice. The revised form eliminates duplicate reference requirements. Each item, test, service, or treatment expected to be denied only needs to be identified once on the form along with the possible reasons Medicare may not pay and an estimate of costs.
- Revised options presented to patients: the language presented in options presented to patients has been revised for clarity purposes however, patients still have three options:
- Option 1: accept the service; allow Medicare to process a determination of coverage; accept financial responsibility if Medicare denies.
- Option 2: accept the service; do not submit a request for coverage determination from Medicare; pay out-of-pocket.
- Option 3: refuse to receive any portion of the Services offered.
The revised form maintains its role as a vehicle for transferring possible future financial liability from providers to patients when Medicare expects to deny coverage for those Services.
Although providers are encouraged to maintain uniformity with respect to content and design, providers may pre-print their practice information and logos on their forms and/or use labels or stamps. One-page only format must be maintained for all ABNs.
Completing ABN form fields in correct order
Inaccurate or incomplete notices render both parties unable to bill the patient for Services provided. In order to ensure compliance with regulations requiring accurate completion of notices, field-by-field instructions have been outlined below.
Field a: notification section
Enter your practice name, address and phone number. This information may be incorporated into your logo and/or printed on your notice in advance. Field a may be completed using a variety of methods including typing, writing by hand, using labels or stamps.
The practice information entered into field a must appear on your form prior to delivery to your patient. Field a cannot be completed after delivery of the form to your patient.
Field b: patient name
Enter your patient’s first name and last name. Include middle initials if shown on his/her Medicare card. If either initial is omitted or misspelled, failure to correct this error does not invalidate your notice as long as you identify your patient’s name.
Field c: optional – Identification number
You may enter an Identification number into field c if desired. You may use either a medical record number or a patient id. Do not enter either of the following medi-care numbers in field c : health insurance claim number (hic), Medicare Beneficiary Identifier (MBI) or Social Security Number
Field d: description of service(s)
Many practices experience difficulty in completing field d. According to CMS, each blank designated “d” must be completed for the notice to be valid.
Identify specifically each item/service/test/procedure/equipment that you reasonably anticipate Medicare may deny payment for. If there exists a possibility that some components of a partial covered service may be denied by Medicare, please describe those components as well. Using general descriptions such as “wound care supplies” is sufficient because itemized lists are not required.
If repeated or ongoing care is anticipated as potentially non-reimbursable (such as bi-weekly blood draws), please detail both frequency/durations.
Field e: reason why Medicare may deny payment
For each description listed in field d, you must provide a simple explanation for why Medicare may deny payment for each service. three examples of explanations given by CMS follow:
- “This test is not reimbursed by Medicare for your condition.”
- “You may perform this test too frequently (more often than allowed).”
- “The test is classified as experimental/research use.”
Be sure to avoid using technical language and explain in simple terms why Medicare will probably deny payment for each service. Failure to Complete field e will invalidate your notice.
Field f: estimated costs
Complete this section with a good faith estimate of cost incurred due to Services provided. CMS has provided considerable latitude in estimating costs. Estimates may vary within $100 dollars or 25% greater/lesser than actual costs incurred whichever amount is greater. Estimates exceeding actual costs incurred by patients will harm neither party since patients’ costs were lower than initially estimated.
If your notice includes multiple Services provided, you can combine total costs into a single estimate.
Field G: Beneficiary Options
The beneficiary must check one of the three options listed. The provider must not pre-select an option on behalf of the patient. Doing so invalidates the notice.
If there are multiple items listed and the patient wants to receive some but not all, you can use additional ABNs or cross out the services the patient does not want
If the patient refuses to choose an option, note the refusal on the form. You can list witnesses, but it is not required.
Field H: Signature and Date
The beneficiary must sign and date the form. This is the final step. The patient cannot sign before the rest of the form is completed. The provider must review the ABN with the patient and answer any questions before the patient signs.
Field I: Provider Signature
The notifier must sign and date the form to confirm that the notice was given. For a valid notice, providers must date the form in both Section I and the patient acknowledgment section (H). If you fail to date the ABN in both locations, it is invalid.
What Happens After the Patient Signs the ABN?
The signature is not the end of the process. What happens next depends on the option the patient selected and on how Medicare adjudicates the claim.
Under Option 1, you furnish the service and submit the claim to Medicare with the GA modifier attached to the relevant line. Medicare issues its determination. If the claim is denied, the denial assigns financial responsibility to the patient, and you may bill the patient directly for the service. If Medicare pays the claim, the patient owes nothing beyond normal cost sharing.
Under Option 2, the patient receives the service and pays out of pocket, and no claim is submitted. Under Option 3, no service is furnished and nothing is billed.
Refunds When Medicare Pays
If you collected payment from the patient at the time of service under Option 1 and Medicare later pays the claim, you must refund the patient promptly. The ABN transfers liability only for services Medicare actually denies. Holding patient money for a service Medicare paid creates a compliance problem and a patient relations problem at the same time.
The Patient Keeps Their Appeal Rights
Signing an ABN does not waive the beneficiary’s right to appeal. Option 1 exists precisely so the patient can require an official Medicare decision, and once that decision is issued, the patient can challenge it through the standard appeal process: redetermination by the Medicare Administrative Contractor, reconsideration by a Qualified Independent Contractor, a hearing before an Administrative Law Judge, review by the Medicare Appeals Council, and finally federal district court. If an appeal overturns the denial, Medicare pays the claim and any amount collected from the patient for that service must be refunded.
For the practice, this means an ABN is not a shield against the appeal process. It is documentation that the patient made an informed choice, and it holds up only when the notice itself was valid.
When the Patient Refuses to Sign
A patient sometimes accepts the form but refuses to choose an option or sign. Note the refusal directly on the original notice, including the date and the circumstances. You may list witnesses to the refusal, although witnesses are not required. If a patient refuses to sign a correctly delivered ABN, consider whether to furnish the service at all, since you cannot shift liability without a signed notice. The exception is when withholding the service would endanger the patient’s health or safety, in which case care comes first and the financial exposure is absorbed.
Claim Modifiers for ABN
The ABN itself is not submitted with the claim. However, you must attach the correct modifier to the claim line to indicate that you issued a valid ABN.
| Modifier | When to Use |
| GA | You issued a mandatory ABN as required by the payer’s policy, and it is on file. Keep the signed ABN in your records. |
| GX | You issued a voluntary ABN for a service that Medicare never covers (statutorily excluded) |
| GY | You did not issue a notice because it is not required. The service is statutorily excluded. |
| GZ | You expect Medicare to deny the service as not medically necessary, but you did NOT issue an ABN. The patient cannot be billed. |
Common errors that void an ABN
Incomplete d field(s)
The most frequent violation is Failure to fill out all seven (7) d fields. In every case of the d field, the service description must be entered.
Reason for not covering – blank or vague
Any time E field is either blank or contains some vague language; the ABN is void. Plainly state the reason for not covering each service.
Estimate costs – missing
To void the ABN, simply fail to make a good faith estimate in field f. To create a fair estimate, determine what you know about the service and/or procedure you intend to perform and estimate accordingly.
Choosing the patient’s options beforehand
You cannot preselect the patient’s Option choice on their behalf. Doing so will void any notice you provide to them.
Providing an ABN after the service has been provided
The ABN must be provided to the patient prior to service with enough time for the patient to make an informed decision. After-the-fact notice does not have legal effect.
Using an older version of the ABN
Previous versions of the ABN were valid only until May 12, 2026. After that date, you must use the updated CMS-R-131.
Using an incorrect/modified version of the ABN
Only the standardized version of the approved Form can be used. Modifying or altering either the layout or language of the standardized Form will also invalidate the notice.
Issuing the ABN in an emergency or under pressure
A notice delivered during an emergency, or so close to the service that the patient had no real time to decide, is treated as invalid. Deliver the ABN far enough in advance that the patient can consider the options, ask questions, and decline the service without pressure.
| Did you discuss the ABN with the patient? Simply presenting the Form for signature without discussing it with the patient will not satisfy the requirements by CMS. Review the Form with the patient and discuss if necessary. Document your discussion if necessary.
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How Long Is an ABN Valid?
A single ABN can cover an extended course of treatment for up to one year, provided the notice identifies the services, the frequency, and the duration of the treatment it covers. A patient receiving recurring services, such as repeated laboratory draws or a series of therapy visits, does not need a new form at every encounter if the original notice described the full course.
Two events end the validity of an existing ABN before the year is up. If the treatment changes, meaning new services are added or the described care is altered, a new notice is required for the changed care. And if the course of treatment extends beyond one year, a fresh ABN must be issued for the period past the anniversary of the original notice. Practices running recurring-service schedules should calendar ABN expiration the same way they calendar authorization expirations, because an expired notice provides no liability protection for the visits that follow it.
Practical strategies for proper ABN usage
Replace all old templates by May 12, 2026
The new standardized forms are available on the CMS beneficiary notice initiative website. Use current forms.
Fill out every required field completely
Do not leave any required field blank. If even One required field is missing, then the entire Form will be treated as void.
Provide advance notice
Provide the ABN to the patient before the service is provided. This allows sufficient time for the patient to consider his options.
Review the Form and explanation with the patient
Discuss the reason for denial, estimated cost of service and options with the patient. Answer any questions they may have about the service.
Retain signed forms
Keep original signed forms on file. You must produce these upon request if audited by Medicare.
Avoid routine use of ABNs
Issue an ABN only when there is a specific reasonable basis for believing that Medicare will deny coverage for that particular service for that particular patient.
Final Thoughts
The ABN is a valuable asset in helping protect your revenue from denials made by Medicare. As stated previously, this notice enables you to assign the burden of payment for the non-covered service from Medicare to the patient. However, this can only occur when proper usage is utilized. An incomplete or improperly completed ABN will result in no notice being issued to the patient. Therefore, you will be responsible for paying for the denied service.
As stated above, the format of the updated Form has been simplified and improved. The updated version is effective immediately. You have until May 12, 2026, to begin using it. The rules governing when to utilize an ABN have remained unchanged since its inception. However, remaining in compliance continues to be a major area of concern by Medicare enforcement personnel.
Complete every field. Provide adequate time for patient consideration. Review with patience. Maintain copies of completed & signed notices. Attach correct modifier to claim. Only utilize when a reasonable basis exists for denial. Follow these steps & you will retain your right to bill the patient when coverage is denied by Medicare.
FAQs
What is the difference between a mandatory and voluntary ABN?
Mandatory ABN: mandatory ABNs are issued when Medicare may deny a covered service. You must issue the mandatory ABN to assign the burden of payment from Medicare to the patient.
Voluntary ABN: voluntary ABNs are optional. They should be utilized for services which Medicare never covers such as routine physicals or cosmetic procedures. Although they inform patients regarding their responsibilities, when you do issue a voluntary ABN, report the GX modifier on the claim line.
Can I provide an ABN after providing services?
No. The ABN must be made available to the patient prior to providing services allowing sufficient time for him/her to make an informed decision. Providing an after-the fact ABN has no legal effect. You will not be permitted to bill the patient if you fail to provide advance notice.
What happens if I fail to use current versions of ABN forms?
Older versions of the ABN were valid only through May 12, 2026. After that date you will need to use updated CMS-R-131 versions of the Form. Failure to use current versions of the Form means you will not be permitted to assign the burden of payment from Medicare to the patient. You will remain responsible for the full amount of denied claims.
What is the GZ modifier and why shouldn’t I use it?
GZ modifier: indicates expectation by provider that Medicare will deny covered service as not medically necessary but did not issue an ABN. This is known as “bill at own risk”. You will not be permitted to bill the patient for the non-covered service and you will be responsible for full loss. Avoid using GZ by issuing a valid ABN whenever you anticipate denial by Medicare.
Must I issue an ABN to every Medicare patient?
No. Routinely issuing ABNs to every Medicare patient is restricted and can result in red flag auditors’ visits. Issue an ABN only when you have a specific reasonable basis to believe Medicare will deny coverage for that specific service for that specific patient.
Can you bill a patient without an ABN?
Only in limited cases. If the service is statutorily excluded from Medicare coverage, such as a routine physical or cosmetic procedure, you can bill the patient without any notice, because Medicare never pays for those services. For services Medicare normally covers, the answer is no. If you expected a denial and did not deliver a valid ABN before the service, the financial loss is yours, and appending the GZ modifier signals exactly that on the claim.
Is an ABN used for Medicaid?
No. The ABN is a Medicare fee-for-service notice and applies only to Original Medicare beneficiaries. It is not used for Medicaid, Medicare Advantage plans, or commercial payers. Medicaid programs and private plans have their own notice and waiver processes, which vary by state and by contract, so check the specific payer’s requirements before assuming any notice transfers liability to the patient.
How long is an ABN valid?
A single ABN can cover a defined course of treatment for up to one year when the notice describes the services, frequency, and duration. If the treatment changes, a new notice is required for the changed care, and if care continues past one year, a fresh ABN must be issued. An expired or outdated notice provides no protection for the services furnished after it lapses.
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Errors related to your practice’s ABNs can cost you money! One partially completed Form, one missing signature, or one delayed notice can lead to thousands lost dollars in unreimbursed services.
UControl Billing Experts doesn’t just process claims; we help protect you before your claims are ever processed. Our staff reviews all your ABNs to ensure completeness. We confirm that you’ve applied the appropriate modifiers to your claims. We educate your staff on when to issue a notice and how to properly administer the process. We ensure your compliance so you’ll never lose money due to preventable losses.
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