Commonly Used Medicare Modifiers – GA, GX, GY, GZ

Medicare ABN Specific Modifiers – GA, GX, GY, GZ

Medicare-ABN-GA-GX-GZ-GY-ModifiersWe get a lot of questions at our medical billing company about what modifiers to use when submitting charges to Medicare to indicate that an ABN (Advanced Beneficiary Notice) was given or not given to the patient.  These are the top 4 Medicare modifiers we use.

GA Modifier:

Waiver of Liability Statement Issued as Required by Payer Policy.

  • This modifier indicates that an ABN is on file and allows the provider to bill the patient if not covered by Medicare.
  • Use of this modifier ensures that upon denial, Medicare will automatically assign the beneficiary liability.

GX Modifier:

Notice of Liability Issued, Voluntary Under Payer Policy.

  • Report this modifier only to indicate that a voluntary ABN was issued for services that are not covered.
  • Medicare will automatically reject claims that have the –GX modifier applied to any covered charges.
  • Modifier –GX can be combined with modifiers –GY and –TS (follow up service) but will be rejected if submitted with the following modifiers: EY, GA, GL, GZ, KB, QL, TQ
  • Additional information on the –GX modifier can be found at:

GY Modifier:

Notice of Liability Not Issued, Not Required Under Payer Policy.  This modifier is used to obtain a denial on a non covered service.  Use this modifier to notify Medicare that you know this service is excluded.

GZ Modifier:

Item or Service Expected to Be Denied as Not Reasonable and Necessary.  When an ABN may be required but was not obtained this modifier should be applied.

Additional information can be found at:

Medicare Modifiers - Medical Billing Services

About Manny Oliverez

has years of healthcare, business and teaching experience. He has a passion for helping physicians get paid for the work they do. Manny likes to blog, act and cook. READ MORE
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  1. Debbie Farrell says:

    Being denied consults when billing Medicare because not using proper modifier (was using AH), but can find no human being to talk to at Medicare and havce been looking on-line and can’t find. Any Help? This is for a psychological practice. It is my understanding the new consult code is 90791 (90792 for our psychiatrists).

    Thanks, Debbie

  2. Doug Harder says:

    We are an ambulance company. We are getting Medicare denials transporting patients to therapeutic/diagnostic centers (D Modifier)i.e RD is residence to diagnostic center & DR is the return modifier. The facilities are NOT physicians (P Modifier) & not hospital (H modifier). Why are we getting denials for bona fide procedures/ICD9 codes in these facilities?
    Help. Thanks

  3. This information may be confusing for inexperienced billers. Only the designated “attending physician” is eligible to use the GV modifier. All other claims related to the hospice care must go to the hospice provider. The GW modifier can be selected when it can be shown by documentation that the services are not related to the hospice care.

    Modifiers should never be changed or added to claims unless the documentation has been reviewed and the use of the modifier is appropriate based on the documentation.

    Mary Lutes, CPC

  4. What does exj mean at the end of a prescription?

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