An Advance Beneficiary Notice of Noncoverage (ABN) is required whenever a Medicare provider, supplier, or physician expects that Medicare will deny payment for a specific item or service. The ABN (Form CMS-R-131) serves one core purpose: to let you know, before you receive care, that you may have to pay out of pocket. If a provider doesn’t give you a properly completed ABN before delivering the service, they generally cannot bill you for it.
Services That Trigger a Mandatory ABN
Providers must issue an ABN in several specific situations. The most common is when a service doesn’t meet Medicare’s “reasonable and necessary” standard. That includes care that isn’t indicated for your diagnosis, treatment that’s considered experimental or investigational, and services that exceed the number Medicare allows within a given time period for your condition.
Beyond that broad category, CMS requires an ABN in these situations:
- Custodial care: Ongoing help with daily activities like bathing or dressing that doesn’t require skilled medical personnel.
- Outpatient therapy: Physical, occupational, or speech therapy services that aren’t considered medically reasonable and necessary for your condition.
- Preventive services exceeding frequency limits: Medicare covers many screenings and wellness services, but only at set intervals. If you want a covered service more often than allowed (a second screening in a year when only one is covered, for example), the provider must give you an ABN.
- Home health services: Before providing care to a patient who isn’t homebound or doesn’t need intermittent skilled nursing care.
- Hospice services: Before caring for a patient who isn’t terminally ill.
- Durable medical equipment, prosthetics, orthotics, and supplies (DMEPOS): Several specific scenarios apply here, covered in detail below.
How It Works for Lab Tests
Laboratory testing is one of the most frequent ABN triggers because Medicare sets strict frequency limits on dozens of common tests. Lipid panels, blood glucose tests, hemoglobin A1c, thyroid function panels, and triglyceride tests all have coverage caps tied to how often they can be repeated for a given diagnosis. If your doctor orders one of these tests sooner than Medicare’s schedule allows, the lab or ordering provider must issue an ABN before drawing your blood. Without it, you can’t be held responsible for the bill.
The specific frequency limits vary by test and by the local Medicare contractor in your area. Your provider’s office should know these limits and flag them before your appointment or lab visit.
DMEPOS Supplier Rules
Suppliers of durable medical equipment, prosthetics, orthotics, and supplies face additional ABN requirements beyond the standard “not reasonable and necessary” trigger. An ABN is required before providing you with an item or service when:
- The supplier contacted you through a prohibited unsolicited phone call to sell the product.
- The supplier hasn’t met Medicare’s supplier number requirements.
- A non-contract supplier is providing an item that falls under Medicare’s competitive bidding program in your area.
- You want the item before Medicare has made an advance coverage determination.
Competitive bidding is particularly relevant if you need items like wheelchairs, oxygen equipment, or diabetic supplies. In designated areas, only contract suppliers can bill Medicare for certain products. If you go to a non-contract supplier, they must tell you upfront that Medicare won’t pay.
Services Medicare Never Covers
There’s an important distinction between services Medicare might deny and services Medicare never covers by law. Statutory exclusions include:
- Routine physical exams not tied to a specific symptom or diagnosis (though Medicare does cover an Annual Wellness Visit, which is different)
- Hearing aids and hearing exams for fitting them
- Eye exams solely for prescribing glasses or contacts
- Most dental care, including fillings, extractions, and dentures
- Cosmetic surgery unrelated to accidental injury or a malformed body part
- Routine foot care like corn removal, callus trimming, and nail clipping
- Orthopedic shoes (unless they’re part of a leg brace)
- Most immunizations, with exceptions for flu, pneumonia, hepatitis B, and COVID-19 vaccines
An ABN is not technically required for these never-covered services because the expectation is that everyone already knows Medicare won’t pay. However, CMS allows providers to use the ABN form voluntarily for these items as a courtesy, and many do. If you’re ever unsure whether something falls into the “never covered” category or the “might not be covered” category, the ABN itself should describe the reason Medicare is expected to deny payment.
Who Issues an ABN
ABNs apply only to Original Medicare (fee-for-service). If you have a Medicare Advantage plan, the equivalent notice is called a different form. For Original Medicare, ABNs can be issued by physicians, practitioners, providers (including hospitals for outpatient services, independent labs, home health agencies, and hospices), and suppliers. Skilled nursing facilities use the ABN specifically for items and services expected to be denied under Medicare Part B.
When an ABN Is Not Required
ABNs are never required in emergency situations. If you arrive at an emergency department, no one needs to hand you paperwork before stabilizing you. The requirement only applies when there’s time to notify you in advance, which is why the form must always be delivered before the service is provided.
What Happens After You Receive One
When you get an ABN, you’re choosing between three options listed on the form. Option 1 means you want the service, you want Medicare billed, and you’ll accept financial responsibility if Medicare denies the claim. This preserves your right to appeal the denial. Option 2 means you want the service but don’t want Medicare billed at all, so you agree to pay out of pocket and give up your appeal rights. Option 3 means you decline the service entirely.
If a provider fails to give you a valid ABN before a service that required one, the provider, not you, absorbs the cost when Medicare denies the claim. The ABN must be delivered to you or your authorized representative before the items or services are provided. A form handed to you after the fact, or one missing the required details about the specific service in question, is not valid.
The most practical thing you can do when handed an ABN is read the reason listed for the expected denial. It should tell you in plain language whether the issue is frequency limits, medical necessity, or a coverage rule specific to your situation. That context helps you make an informed choice among the three options, and it gives you the information you’d need if you decide to appeal.