What modifier is used if an ABN is signed and filed?

• A. GA modifier
• B. GB modifier
• C. GC modifier
• D. GE modifier

Answer: (A)

When a service might not be covered by Medicare, you give the patient an Advanced Beneficiary Notice (ABN). If the patient signs that ABN and you file it with the claim, you attach the GA modifier to that line item. The GA modifier confirms that a waiver of liability statement is on file, meaning the patient has agreed to pay out of pocket if Medicare doesn’t pay. This flags to the payer that the provider has obtained the patient’s consent and that the patient is financially responsible for the service. In practice, this is the standard way to document a signed and filed ABN.