- An Advanced Beneficiary Notice is a notice given by a provider to the patient before rendering service when the provider believes that the service is not going to pay or deny by Medicare insurance as per medicare guidelines and if the same service is denied by medicare then it is a patient liability to pay for the service.
- For example, there are few services that medicare pays once in a year when the provider renders such service twice a year then the provider needs to notify the patient of the same concern.
- The provider must provide a reason in an ABN since the patient should also know that it may be the patient’s liability if it is denied by medicare.
- If the patient does not sign ABN and the service is denied by Medicare then the patient does not need to pay for the service.
- ABN should be sent to Medicare beneficiaries only.
- When a patient signs an ABN and service is denied by medicare then the patient must pay for the service by out-of-pocket or by other insurance coverage.
- When an ABN is signed by the patient then the provider needs to send the claim to medicare first and if it is denied by medicare then it goes to the patient. When an ABN is not signed by the patient then service cannot be directly billed to the patient.
- When a patient refuses to sign an ABN but it is necessary to provide the service for the patient’s health or safety then the sign of the second person who presents when the patient refuses to render the service can be used as a witness and if medicare denies the claim then its patient liability to pay the service.
- The provider does not need to send an ABN for each and every service, there are a few services that medicare never covers then those services can directly bill to the patient once deny by medicare.
Advance Beneficiary Notice (ABN): What It Is and How the 2026 Update Changes Your Workflow
If you’ve ever had a Medicare claim denied because the ABN paperwork wasn’t quite right—or watched a patient walk out confused after being handed a form at check-in—you already know how important getting this process correct can be. The Advance Beneficiary Notice (also commonly called the “advanced beneficiary notice” or simply “ABN”) is one of the most frequently misunderstood documents in medical billing, yet it’s absolutely critical for protecting both your practice and your patients when Medicare coverage is uncertain.
In this guide, we’ll walk through everything billing professionals and patients need to know: what an ABN actually is, when it’s required, the four modifier codes that go with it, and—most importantly—what changed with the March 2026 CMS form update and your hard deadline to switch over.
What Is an Advance Beneficiary Notice (ABN)?
An Advance Beneficiary Notice (ABN) is a standardized form that Medicare providers must give to Original Medicare (Part A and Part B) beneficiaries before delivering an item or service that Medicare is expected to deny as not medically necessary or not covered.
The official form is CMS-R-131, and it serves one main purpose: to inform the patient, in writing, that Medicare will probably not pay—and to let them decide whether they still want the service and are willing to pay out of pocket if the claim is denied.
Think of it as informed financial consent. Without a properly executed ABN, you may not be able to bill the patient for a denied service, even if the denial was predictable. That’s why getting the timing, wording, and documentation right matters so much.
Key point: The ABN applies only to Original Medicare (Part A and Part B fee-for-service). It is not used for Medicare Advantage (Part C) plans, Medicare Part D, or any other insurance. Using an ABN for a Medicare Advantage patient is a compliance red flag that can trigger audit findings.
2026 CMS Form Update — What Changed and Your Deadline
On March 13, 2026, CMS released a redesigned version of the ABN form (CMS-R-131), representing the first substantive update in several renewal cycles. This isn’t just a cosmetic refresh—the language around patient options has been simplified, the layout improved for readability, and the instructions clarified to reduce common mistakes.
Old Form Expiration vs. New Form Validity Dates
- Old form (CMS-R-131 G): Expired and no longer valid for use after May 12, 2026.
- New form (CMS-R-131 H): Valid from March 13, 2026 through March 31, 2029.
Your hard cutover deadline is May 12, 2026. After that date, using the old version is not considered a legally defensible notice. If you issue an expired ABN and a claim is denied, you lose the right to bill the beneficiary—even if they signed it.
What Actually Changed in the Wording and Design
CMS made several improvements in the 2026 revision:
- Simpler patient-option language: The three choice boxes now use shorter, more direct phrasing at an 8th-grade reading level.
- Larger font and better spacing: Designed to be more accessible for older adults with vision challenges.
- Clearer cost-estimate field: The “Estimated Cost” section now includes a brief explanation that the amount is an estimate, not a guarantee, reducing post-service disputes.
- Streamlined header: Contact information and notifier fields are consolidated to reduce form clutter.
The core legal function hasn’t changed—but the redesign reduces the chance that a beneficiary will misunderstand their options or claim they weren’t adequately informed, which strengthens your documentation in the event of an appeal or audit.
Action item: Download the current CMS-R-131 H form directly from the CMS Beneficiary Notices Initiative page and replace any old templates in your practice-management system or paper stock by May 12, 2026.
When Is a Provider Required to Issue an ABN?
You are required to issue an ABN when all three of these conditions are met:
- You reasonably expect Medicare will deny payment for the item or service.
- The denial reason is specifically that the service is not medically necessary or not covered under Medicare guidelines (not a technical or eligibility issue).
- The beneficiary might otherwise assume Medicare will pay.
Common scenarios include:
- A screening test ordered more frequently than Medicare’s coverage policy allows (for example, a screening colonoscopy before the 10-year interval).
- A service that doesn’t meet Medicare’s medical-necessity criteria for the patient’s diagnosis.
- An upgraded or experimental item when Medicare only covers the standard version.
- A procedure that has an LCD (Local Coverage Determination) exclusion for the patient’s condition.
Mandatory vs. Voluntary ABNs
- Mandatory ABN: You must issue one if you want the option to bill the patient after a predictable denial. If you don’t issue it, and Medicare denies the claim, you eat the cost—you cannot bill the beneficiary.
- Voluntary ABN: You may issue one if you’re uncertain whether Medicare will pay, but it’s not absolutely expected to deny. Voluntary ABNs are less common but can protect you in gray-area cases.
When an ABN is not required:
- The service is never covered by Medicare (statutory exclusion)—in this case, you should notify the patient, but a formal ABN isn’t the right tool; a different notice or simple disclosure works better.
- The service is bundled into a global code or already included in another covered service.
- The patient is not a Medicare beneficiary (e.g., private insurance, self-pay, Medicare Advantage).
The 3 ABN Options Explained (Patient Perspective)
When a patient receives an ABN, the form presents three choices. Here’s what each one means in plain language:
Option 1: “I want the items or services listed. You may ask to be paid now, but I also want Medicare billed for an official decision on payment, which is sent to me on a Medicare Summary Notice (MSN). I understand that if Medicare doesn’t pay, I am responsible for payment, but I can appeal to Medicare by following the directions on the MSN.”
Translation: Go ahead with the service. Bill Medicare first, and if they deny it, I’ll pay—but I also get the right to appeal the denial.
This is the most common choice and gives the patient maximum flexibility.
Option 2: “I want the items or services, but do not bill Medicare. You may ask to be paid now as I am responsible for payment. I cannot appeal if Medicare is not billed.”
Translation: Go ahead with the service, but skip Medicare altogether. I’ll pay you directly, and I understand I’m giving up my appeal rights.
Patients rarely choose this unless they want to avoid the delay of claim processing or prefer to keep the service off their Medicare record.
Option 3: “I don’t want the items or services. I understand with this choice I am not responsible for payment, and I cannot appeal to see if Medicare would pay.”
Translation: I’ve decided not to get the service. No charge, no claim, no appeal.
This option protects the patient from unexpected costs and is sometimes chosen when the out-of-pocket estimate is higher than the patient is willing or able to pay.
What Happens If a Patient Refuses to Sign an ABN?
If the patient refuses to sign, you have two choices:
- Do not provide the service. This is the safest route if the service is elective and you’re certain Medicare will deny.
- Provide the service anyway, but understand you cannot bill the patient if Medicare denies it. You can still submit the claim to Medicare, but if it’s rejected, you absorb the cost. The unsigned or refused ABN offers no financial protection.
Important: An unsigned ABN is not the same as no ABN. Document the refusal in the patient’s chart (“Patient verbally declined to sign ABN for [service]; chose to proceed without signing”) and retain the blank form. This shows you attempted proper notice, which can be helpful if the encounter is ever audited, even though it doesn’t allow you to bill the patient.
You should never require a patient to sign an ABN as a condition of receiving emergency or urgent medically necessary care—that would be considered coercive and is prohibited.
ABN Modifiers Explained — GA, GX, GY, GZ
Once you’ve issued an ABN and the patient has made a choice, you must append the correct modifier to the claim to tell Medicare (and your MAC) what happened. Using the wrong modifier is one of the top reasons ABN-related claims get kicked back or flagged in audits.
Here’s the definitive breakdown:
| Modifier | When to Use It | What It Tells Medicare | Patient Liability |
|---|---|---|---|
| GA | ABN is on file, signed by the patient, for a service expected to be denied as not medically necessary | “We have a signed ABN; if you deny this, we can bill the patient.” | Patient is liable if denied |
| GX | ABN is on file, signed, for a service you know is a statutory non-covered benefit (voluntary notice of exclusion) | “We notified the patient this is never covered; no need to process—just deny and we’ll bill the patient.” | Patient is liable |
| GY | Service is statutorily excluded or not a Medicare benefit, and no ABN was issued (or not required) | “This is non-covered by law; deny it outright.” | Patient is liable, but claim may auto-deny without review |
| GZ | Service is expected to be denied as not medically necessary, but no ABN was obtained | “We think this will be denied, and we don’t have patient consent to bill them.” | Provider is liable—you cannot bill the patient if denied |
Pro tip: The difference between GA and GZ is whether you got the signature. The difference between GX and GY is whether you bothered with a notice. The difference between GA and GX is whether the denial reason is medical necessity (GA) or statutory exclusion (GX). Knowing these distinctions prevents you from inadvertently waiving your right to collect.
Example workflow:
- Patient needs a repeat PSA test at 9 months post-treatment; Medicare covers it annually. You issue an ABN, patient signs Option 1. → Use modifier GA.
- Patient requests cosmetic botox (never covered). You issue a notice explaining it’s excluded, patient signs. → Use modifier GX.
- Same cosmetic botox, but you don’t issue any notice and just bill the patient directly. → Use modifier GY.
- Patient wants an MRI that doesn’t meet LCD criteria, but you forgot to get an ABN before the scan. → Use modifier GZ and accept you can’t bill the patient if it denies.
For more detail on how these modifiers interact with other billing scenarios, see our related guides on the GA modifier, authorization requirements, and denial code CO-22 (which is often tied to missing or incorrect ABN documentation).
Common ABN Mistakes That Trigger Denials or Audits
Even experienced billing teams make these errors. Avoiding them can save you thousands in write-offs and keep you off your MAC’s audit radar.
1. Using “Blanket” ABNs
A blanket ABN is one that’s issued routinely to every patient, or for broad categories of service, without an individualized reason. For example, handing every diabetic patient an ABN that says “glucose monitoring supplies” with no specific explanation.
Why it’s prohibited: CMS requires that each ABN state the specific item or service and the specific reason Medicare may not pay. A generic, one-size-fits-all notice doesn’t give the patient enough information to make an informed choice, and auditors will disallow it.
Fix: Customize each ABN with the exact service (CPT/HCPCS code is helpful), the individual patient’s situation, and the reason (e.g., “frequency exceeds coverage limits” or “diagnosis does not support medical necessity per LCD”).
2. Issuing an ABN to QMB Beneficiaries
Qualified Medicare Beneficiaries (QMBs) are dual-eligible individuals whose state Medicaid program pays their Medicare cost-sharing. You cannot bill a QMB for any Medicare cost-sharing, even with a signed ABN. Doing so is a federal violation.
If you issue an ABN to a QMB and they sign it, the signature is void—you still can’t collect. The patient’s QMB status overrides the ABN.
Fix: Check eligibility before issuing an ABN. If the patient is QMB, you must accept the Medicare-allowed amount (plus any Medicaid payment) as payment in full, and you cannot balance-bill.
3. Issuing the ABN Too Late
The notice must be given before the service is rendered—ideally at the time of scheduling or check-in, not after the procedure is complete. An ABN signed post-service is not valid and won’t protect your right to bill the patient.
Fix: Build ABN review into your pre-service workflow, especially for elective or non-urgent services where coverage is uncertain.
4. Missing or Inaccurate Cost Estimates
The ABN form has a field for “Estimated Cost.” Leaving it blank or writing “varies” weakens the notice. The patient has a right to know, at least approximately, what they’ll owe.
Fix: Provide a reasonable, good-faith estimate. It doesn’t have to be exact, but it should be in the ballpark. Document how you arrived at the estimate (fee schedule, historical allowed amounts, etc.).
5. Using an Expired ABN Form
As noted earlier, using the old CMS-R-131 G form after May 12, 2026 makes the notice invalid. Even if the patient signed it, CMS and MACs will not honor it.
Fix: Audit your forms now. If you’re still using pre-2026 stock or outdated templates in your EHR, replace them immediately.
ABN vs. Medicare Advantage / MOON Notices Know the Difference
ABN vs. Medicare Advantage
An ABN is used only for Original Medicare (Part A and Part B). If your patient has a Medicare Advantage plan (Part C), the plan’s own prior-authorization and coverage rules apply. You should follow the MA plan’s notification and appeal procedures, but you do not issue a CMS ABN.
Using an ABN for a Medicare Advantage patient can create compliance problems, because the patient may believe they have rights under Original Medicare rules when they actually don’t. Always verify the patient’s coverage type before issuing any financial-liability notice.
ABN vs. MOON (Medicare Outpatient Observation Notice)
A MOON is a different CMS-required notice, used in hospital outpatient or observation settings, to inform beneficiaries that they are an outpatient (not admitted), which affects their Part A vs. Part B cost-sharing and SNF eligibility.
- ABN = “Medicare might not pay for this service; here’s your financial choice.”
- MOON = “You’re an outpatient, not admitted; here’s what that means for your costs and benefits.”
Both are required in different situations; they do not replace each other. A hospital might issue both to the same patient if, for example, the patient is in observation (MOON required) and is receiving a service expected to be denied (ABN required).
For more on the interplay between authorization, referral, and coverage notices, see our guides on authorization in medical billing and the difference between authorization and referral.
Frequently Asked Questions
An ABN (Advance Beneficiary Notice) is a standardized CMS form (CMS-R-131) that providers must give to Original Medicare patients before furnishing a service that Medicare is expected to deny as not medically necessary or not covered. It informs the patient of the potential denial and allows them to choose whether to proceed and accept financial responsibility.
An ABN is required when you reasonably expect Medicare will deny a covered service as not medically necessary, and you want to preserve the right to bill the patient if the denial occurs. It is not required for services that are never covered by Medicare (statutory exclusions), though you should still inform the patient in those cases.
If you didn’t obtain a signed ABN and Medicare denies the service as not medically necessary, you cannot bill the patient—you must write off the charge. The only exception is if the service falls under a statutory exclusion (modifier GY), in which case the patient can be billed even without an ABN, though it’s still best practice to notify them in advance.
GA: Signed ABN on file; service expected to be denied as not reasonable and necessary.
GX: Signed notice on file; service is a known statutory exclusion (never covered).
GY: Service is statutorily excluded; no ABN issued.
GZ: Service expected to be denied as not reasonable and necessary; no ABN obtained—provider liable.
Use GA when you have the signature and the issue is medical necessity. Use GZ when you should have gotten one but didn’t.
No. The ABN is only for Original Medicare (Part A and Part B fee-for-service). Medicare Advantage plans (Part C) have their own coverage, notification, and appeal processes. Issuing a CMS ABN to a Medicare Advantage beneficiary is incorrect and can cause compliance issues.
A blanket ABN is a generic notice given to all patients or all patients in a certain category, without specific detail about the individual service or reason for potential denial. CMS prohibits blanket ABNs because they don’t provide the individualized information a beneficiary needs to make an informed financial decision. Each ABN must describe the specific service and the specific reason Medicare may not pay.
Yes. CMS released a revised ABN (Form CMS-R-131 H) effective March 13, 2026. The old form expired, and you must stop using it by May 12, 2026. The new form is valid through March 31, 2029. Update your templates, EHR forms, and paper stock now to avoid issuing an invalid notice.
Key Takeaways
- The Advance Beneficiary Notice (ABN) is a required CMS form that protects both patients and providers when Medicare coverage is uncertain.
- A new version (CMS-R-131 H) took effect March 13, 2026, with a hard switchover deadline of May 12, 2026—using the old form after that date invalidates the notice.
- ABNs apply only to Original Medicare Part A and Part B, not Medicare Advantage, Part D, or other coverage.
- The form gives patients three choices: proceed and let Medicare decide (most common), proceed and self-pay without billing Medicare, or decline the service.
- Modifiers GA, GX, GY, and GZ tell Medicare whether you obtained a signed ABN and what kind of denial you expect; using the wrong modifier can cost you the ability to bill the patient.
- Common mistakes—blanket ABNs, late notices, missing cost estimates, QMB billing violations, and expired forms—are audit red flags that can result in write-offs and compliance penalties.
- Always issue the ABN before the service, make it specific to the patient and service, and document the patient’s choice in the medical record.
Disclaimer: This article is for general informational purposes about medical billing procedures and does not constitute legal, medical, or coding advice. ABN requirements can vary by payer and MAC jurisdiction; verify current CMS guidance and consult your compliance officer before making billing decisions based on this content.
About This Guide
This guide was written for medical billing professionals, practice managers, and Medicare beneficiaries seeking a comprehensive, current resource on Advance Beneficiary Notices. It incorporates the latest CMS updates as of 2026 and is designed to be a practical, actionable reference for day-to-day billing operations.
For related topics, explore our guides on denial code CO-22, denial code 16, the GA modifier, authorization in medical billing, and the difference between authorization and referral.
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