Key takeaways
- GA, GY and GZ tell Medicare why you expect a denial and who is financially responsible for it.
- GA: you expect a denial and a signed ABN is on file. GZ: you expect a denial and there is no ABN. GY: the item is statutorily excluded or not a Medicare benefit.
- Without a valid ABN, the supplier usually cannot bill the patient for an item Medicare denies as not reasonable and necessary.
- Use the modifier that matches the facts, and keep the signed notice with the claim file.
What these modifiers do
Some items or services will not be paid by Medicare. In those cases the supplier tells Medicare up front by adding a modifier, and the modifier also settles who pays if the claim is denied: the patient or the supplier. Getting this right protects both your revenue and your patient relationships.
These rules apply to Medicare. Other payers have their own notice and liability rules, so check the contract.
GA, GY and GZ at a glance
| Modifier | What it says | Who is responsible if denied |
|---|---|---|
| GA | Waiver of liability statement on file: a signed ABN was obtained and a denial is expected | The patient, when the ABN is valid |
| GZ | Item expected to be denied as not reasonable and necessary, and no ABN on file | The supplier, as a rule |
| GY | Item or service is statutorily excluded or does not meet the definition of a Medicare benefit | The patient; an ABN is not required for items that are never covered |
The Advance Beneficiary Notice (ABN)
The ABN is a written notice, on the CMS form, that tells the patient Medicare may not pay for an item and that the patient may have to pay. It must be given before the item is delivered, in a form the patient can understand, and signed. The supplier keeps a copy. A notice that is late, incomplete or unsigned does not protect the supplier.
Some suppliers also give a voluntary notice for items that are never covered. Medicare has a separate modifier for that case, so confirm the current rules before you use it.
Which modifier to choose
- The item is never a Medicare benefit (for example, something outside the benefit category): use GY.
- The item is normally covered but this patient may not meet the criteria, and you have a signed ABN: use GA.
- The same situation, but no ABN: use GZ, and expect to write off a denial.
Where a policy already says the item is not covered in the patient’s situation, ask your coder how to apply it before you bill.
Common mistakes
- Using GA without a valid signed ABN in the file.
- Collecting an ABN after delivery.
- Billing the patient after a GZ denial.
- Using GY for an item that Medicare covers in some cases.
- Not tracking GZ denials to see where ABNs are being missed.
GA, GY and GZ FAQ
What does the GY modifier mean?
GY means the item or service is statutorily excluded or does not meet the definition of a Medicare benefit. It tells Medicare you know the item is not covered.
What is the GZ modifier?
GZ means you expect Medicare to deny the item as not reasonable and necessary and you do not have a signed ABN on file. The supplier is generally responsible for the denied amount.
What does the GA modifier mean?
GA means a signed ABN is on file and a denial is expected. If the notice is valid, the patient can be billed.
When do I need an ABN for DME?
When a supplier believes Medicare may deny an otherwise covered item as not reasonable and necessary, and wants to be able to bill the patient. Items that are never covered do not need one.
Can I bill the patient after a GZ denial?
As a rule no. Without a valid ABN the supplier usually bears the loss, so confirm your Medicare obligations before billing the patient.