Health Insurance Companies Process 1 in 5 Claims Wrong.

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

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

We get a lot of questions at our medical billing company about which modifiers to use when submitting charges to Medicare. Specifically, we are often asked how to indicate whether or not an ABN (Advanced Beneficiary Notice) was 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.  This modifier should be applied when an ABN may be required but was not obtained.

Additional information can be found at:

Print Post & Download PDF
In a 6 month period Capture Billing increased our Family Practice's revenue by over $100,000 - Quote

About The Author

Leave a Comment

Your email address will not be published. Required fields are marked *

103 thoughts on “Commonly Used Medicare Modifiers – GA, GX, GY, GZ”

  1. blank

    Can a modifier be used for G0103 in a primary care setting if it’s only used for reporting for an Annual Wellness G0438/G0439 ? We keep getting denials for invalid clia#. How do we obtain the correct clia?

  2. blank


  3. blank

    Medicare denied code A4222 billed with Home POS as CO4 – Missing modifier and required modifier, Which modifier should we append to get it pay ? Please suggest

  4. blank

    I recently booked a vacation through My Travel Royalties, and I couldn’t be happier with the experience. From the user-friendly interface to the competitive prices and excellent customer service, My Travel Royalties is the ultimate online booking platform for travelers.

    What impressed me the most was the wide selection of destinations and vacation packages available. Whether you’re looking for a romantic getaway or an adventure-packed trip, My Travel Royalties has something for everyone. And with customizable packages, you can tailor your vacation to your specific needs and preferences.

  5. blank

    Which CPT code should be used for Well Women Exam when patient has commercial Medicare (i.e Aetna MCR, Humana KY, Cigna MCR, etc)?

  6. blank

    Unbelievable. And I’m sure the patients have not been advised as in informed consent.. Medicare and Medicaid right the undesired class oh and veterans. Unacceptable. Pay people and models like u .. unbelievable and people are not told.. u fucking suck and have no empathy or compassion.. God will humble u in his own way u sorry sack of greedy shit..

  7. blank

    Does private/ commercial insurance take ABN modifier? We keep billing private insurance for codes that have ABN modifiers but not getting a PR for a code. What should be used to bill private insurance so that they adjudicate the claim and put it on the patient’s responsibility?

  8. blank
    Jeannie Elaine Sitton

    So medicare does not cross over the 97124 code with 59 modifier. What modifier do i use so medicare knows its not a covered code but still needs to be submitted to their secondary (BCBS) so they can cover it. Im having issues with medicare crossing the 97124 code over to their secondary

    1. blank

      Try adding GY to it. That’s how I get ours paid. Not all secondaries pay if MC denies it, but the EOB will state that the patient will be responsible for the charge, if it’s not covered. There are some that do pay. For us, it’s mostly government policies. If they do cover, it will be paid with the GY code.

    2. blank

      To bill out my Medicare patient (who has secondary Aetna) I put on the claim 97124 modifier GY, GP.
      If the patient has a crossover from Medicare to Aetna Medicare will send the claim to Aetna.
      I bill out the 97124 separately.

  9. blank

    For mail order nebulizer pharmacies what modifier can be used for early filing if shipped too early due to holidays

  10. blank

    We have a small outpatient clinic in Texas that includes OT, PT and Speech therapy. We bill Medicare and Medicaid along with several other insurances. Does anyone know of a blog or resource that specifically provides information on billing… modifiers.. codes etc. ? TY!

  11. blank

    What Modifier can be use for same or similar ? Patient lost her item and received a second one within the 5 year rule. ?

  12. blank

    We have a patient that was seen by one of our LPC and the patient has Medicare as Primary and BC as secondary. Since LPC’s are not eligible to contract with Medicare, how should the claim be handled? Do we submit to Medicare with the GY modifier for denial? Or is there a way to bypass Medicare submission and bill to secondary?

  13. blank

    Hi! This is kind of off topic but I need some help from an established
    blog. Is it tough to set up your own blog? I’m not very techincal but
    I can figure things out pretty fast. I’m thinking about setting up my own but I’m not sure where to begin. Do you have any ideas
    or suggestions? With thanks

  14. blank

    We have a patient that was seen by one of our LPC’s which initially told us they had BCBS. Come to find out, patient has Medicare as Primary and BC as secondary. Since LPC’s are not Eligible to contract with Medicare, how should the claim be handled? Do we submit to Medicare with a particular modifier for denial? Or is there a way to bypass Medicare submission and bill to secondary?
    Appreciate the assistance!

  15. blank
    Dorothy R Sutton

    AT means “active treatment”. If you do not use it medicare will not pay because medicare does not pay for routine maintenance, only acute treatment.

  16. blank

    Hello Mr. Oliverez,
    We billed a claim to DMERC for L1833 (Competitive Bidding) with KV & LT modifier attached to it but got denied. We rebilled it with just the KV modifier & is still denied. According to DMERC rep, another modifier is needed in order to process the claim & we added KX but claim became Invalid.
    Could you pls. let us know what other modifier can we use?
    Appreciate your help.
    Thank you!
    Monique D.

  17. blank

    When filing a claim for L3020 to Medicare and wanting a denial but for it to be put to patient responsibility, are the correct modifiers just RTGY (or LT depending on the side) when you have a signed ABN? No KX is required?

  18. blank

    I work for a DME provider and sometimes we just need to get a denial for equipment we know is not covered.
    normally we have to deliver something before billing . My question is can we use the GY modifier and not provide the equipment.

  19. blank
    Chiropractic Billing Services

    Thanks for the valuable information. I really admire the Well-researched content of the blog, I must say the facts in the blog is pretty much convincing.

  20. blank

    That’s good to know that some modifiers will denote that a service sin;t covered by Medicare. I feel like that would be a good thing to look into if you are planning on going on medicare. I’ll be sure to look into any modifiers that may apply if I decide to use medicare when I get a bit older.

  21. blank

    I own a physical therapy practice and we are experiencing a new change with secondary insurance plans that become primary when the Medicare threshold has been met and we use a GA modifier. The secondary / now primary insurance plans are denying payment stating that the services were “not medically necessary” based on the use of the GA modifier. So, my question is this, if the services are medically necessary and would normally be covered by Medicare if we had not reached the threshold but we want to avoid a Medicare review by going over the threshold, in order to continue seeing the patient should we use the GY modifier or no modifier? As I stated, the services would normally be covered by Medicare and the use of the GA modifier indicates a service that is NOT reasonable and necessary even though the service continues to be reasonable and necessary. I’m told that if we do not put any modifier then Medicare will deny as a “Contractual Obligation” and the secondary/now primary will not pay. What can we do to be able to continue to see the patient for the necessary services without causing a Medicare review and we can still be paid for the services?

    1. blank

      We use KX, it indicates that the clinician attests that services at and above the therapy caps are medically necessary and reasonable, and justification is documented in the patient’s medical record.

  22. blank

    That’s good to know that you could get modifiers for your medicare. I have been thinking about getting it when I am older, so that’s good to know. I’ll have to look into some more modifiers when the time comes for me to get it.

  23. blank

    I am having issues billing chiropractic treatment. Blue Shield 65 Plus has stated different times I am to used the GA modifier or the GY modifier for 9894 codes, but both times claims denied. I searched for correct modifiers for chiropractic treatment online and I found a page that states we are to bill with AT modifiers if treatment is not considered routine. Help!

  24. blank

    we have billed Medicare part b (DME) for an item with the GA modifier knowing it did not meet medical necessity-we then billed Medicaid as the secondary payor for which they denied. Because we billed with the GA modifier and have a primary remit showing patient responsibility can we now bill the patient even though Medicaid shows no patient responsibility

  25. blank

    I work for a provider that has a Ph.D, with LMHC (Mental Health) and LMFT Marriage and Family) licensure. Medicare will not render these licenses as eligible.
    When I have a client with Medicare as primary and then a secondary, I know you send to primary and then get the EOB from primary and send a claim along with copy of primary eob. Medicare will not issue an EOB denying claims ( I have tried so many ways) and secondary will not accept claims without and EOB from medicare. I have typed letters, sent copies of the exclusion from Medicare handbook, have called many numbers to inquire. I have read more than I would like on the internet on how to handle these claims but no one can tell me how to get secondary to pay without a primary EOB from medicare. What codes, modifiers, letters, etc do I need to simplify this daunting process. Thank you for any help!

  26. blank

    Hello, I work at a hospital and we are having difficulty understanding which modifier(s) to use on physical therapy services. Our physical therapy department indicates that the services do not meet medical necessity. An ABN was issued. We billed with Occur code 32 and GA modifier on the claim, and Medicare paid (perhaps because of the physician’s diagnosis). We have contacted Medicare and still unclear as to what modifier(s) to use. The ABN option #1 was chosen by the patient, wanting us to bill Medicare for services. Should we use GA, or GX, or both? Thanks
    To answer your question, we do Physical Therapy and every time Medicare comes back stating that they have met their cap we refile w/ the KX modifier and they pay without any issues, I’ve actually gotten several hundred back in recoup due to the use of the KX mod. I would try that if you use the GA or GY all that is telling Medicare that it is not medically necessary. KX states that it is, and yes it is also used in DME .

  27. blank

    I have a medical service that would normally be covered, but is not, due to an unusual circumstance. I want to bill Medicare and get a denial with patient responsibility so that I can send it to the secondary insurance. I was thinking that I would bill with a normal first position modifier, and then use GA to indicate that I have an ABN on file, and then also add a GY for a non-covered by statute in this circumstance….is that overkill on the modifiers? Does this creates a “red flag” to Medicare??? Are GA and GY ever used together?

  28. blank

    What modifier is used for DME L0648?
    To answer you question, I always use the KX modifier along with the RT or LT modifiers, that is the only way I’ve ever gotten them paid.

  29. blank

    I bill for a Podiatrist and when I bill any “L” codes I always attach the KX modifier along with the RT or LT that is the only way I have been able to get them paid.

  30. blank
    KaSondra Grandmason

    Does anyone on her bill Priority Health Medicare? If so can you tell me if a patient signs an ABN for frequency do you add the GA onto that line when you bill the claim out?

    Thank you

  31. blank

    Hi, I have a question regarding the GY modifier. I do the billing at a physical therapy practice. I have a patient who has exhausted the therapy cap but the secondary does cover as primary. I need medicare to deny the service and leave the patient responsible that way the secondary can pick up the charges. Would the GY modifier be appropriate?

    1. blank

      Hello Denise —

      The description for the GY modifier states “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.”

      So I would use a GY modifier. Of course, if you submit without the GY modifier you will still get the same denial. But I am of the mind, the more info you sent to make it clear, the better.

  32. blank

    I work for a chiropractor and we bill utilizing AT modifiers but I was recently informed we can’t be using them anymore, Is this true?
    Should I be utilizing the GY codes?

  33. blank

    I work for a lab billing office. My question is, if a procedure code was received with a routine noncover diagnosis code along with a diagnostic dx code, but the diagnostic code doesnt cover the test, would we bill with a -gy or -gz?

  34. blank

    Hi,great work well-done thanks for sharing important information, we are a Medical Centre Contact Lifeaid Medical Centre now! We understand the fear and anxiety of the parents. We provide a friendly environment at our center to make the parents comfortable and to make birthing a lifetime experience.

  35. blank
    Westchester Home PT

    Have you had the experience that Medicare paid for physical therapy services when the claim included the GA modifier? An ABN was done and it was indicated that services are not medically necessary (on the ABN and also in the documentation)? A denial was expected, but the claim was paid because the “diagnosis codes were billable.” Can you please clarify for me, would a GX be more appropriate than a GA modifier if the therapist wants services denied due to lack of medical necessity a.k.a. “skill” in this case? Also, can you please clarify, is a voluntary ABN one that is issued to the patient with the explanation as to why services are not covered under Medicare or is there more to it?

  36. blank

    Hi Manny,

    We bill for home hemodialysis to secondary ins because we are not Medicare certified and recently BCBS wants us to add the GY modifier.

    My question is, do we add the GY modifier to the main CPT code ONLY like 90937/90999 or to EACH HCPCS/CPT codes (procedure/supplies/meds) we bill for each date of service?

  37. blank


    1. blank

      Jennifer. Did you ever get a response to your question? I am wondering if you would use the GY modifier. I am looking for the same answer to your question.

  38. blank

    According to my boss, yes they do. But she also mentioned something regarding an appeal that she did submit to CMS and they denied it. Can you please explain to me in layman terms what actually is the PQRS? I know what it stands for, but I do not understand what it is suppose to do. If she is enrolled in it then she shouldn’t get penalized for it correct? I believe that whomever enrolled her in it didn’t do it correctly. Is there a way to find out?

  39. blank

    I was wondering if you could possibly help with an issue…I do all the billing for a doctor out of our System, she Does use a EMR system, and does prescribe, just not bill out of it (because we do on our end), Medicare is taking out the sequestration, plus an addition tax, due to her not billing out of her system. Is there a code to report to show this? Any information will be greatly appreciated.

    1. blank

      Hi Melinda —

      Depending on the practice, for sequestration, we either increase the write-off by the sequestration amount or have a code, similar to a write-off code, indicating sequestration W/O.

      As far as an additional tax for not billing out of the doctor’s billing system, I am not familiar with that. Do you have more info you can share?

      1. blank

        It comes up on the Medicare EOB as “CO-237, Legislated/Regulatory penalty” along with the “CO-253 Sequestration”

        I was told by my boss that it was due to the doctor doesn’t send the claim directly on her end.

        Thank you for your input.

          1. blank

            Okay sorry to keep bugging you, but I’ve read all this before and I’m still a bit confused, what codes? Is this something that I would report for her, or she would have to do it? I understand that it is “quality control” but to what and how? Thank you again.

  40. blank

    I am trying to bill L0120 and L0174 to UHC.

    Only one is getting paid, what modifier should I use to get both paid. UHC is the only plan that I have trouble with

    1. blank

      Bridgitte you are going to have to talk to UHC to see what their rules are for these codes. They might be considering them similar items since they are both cervical collars and thus not covering one. You know how UHC likes not to pay.

  41. blank

    I want to know if I am billing the claim correctly for upgraded items.
    And yes we have ABN on file.

    A7031-NU-GA 26.27 ($$$$ pt will pay)
    A7031-NU-GK 107.23 ($$$$ medicare will pay)

    1. blank

      We don’t bill for CPAP supplies but I did find some information that may be helpful.

      “GK Reasonable and necessary item ordered when a piece of equipment has been upgraded.

      When billing for upgrades, suppliers must use two lines on the same claim. Line one contains the HCPCS code for the upgraded item the supplier actually provided to the beneficiary with the dollar amount of the upgraded item. If an ABN was obtained, the GA must be billed. If an ABN was not obtained, use the GZ modifier. Line two is billed with the HCPCS code for the reasonable and necessary item with modifier GK and for the full amount of that item.

      Suppliers must also list the upgrade features in Item 19 of the CMS-1500 form or the electronic equivalent.

      GL Item is a medically unnecessary upgrade provided instead of a standard item at no charge to the beneficiary and an ABN does not apply.

      If a supplier furnishes an upgraded DMEPOS item but charges Medicare and the beneficiary for the non-upgraded item, the supplier must bill for the non-upgraded item rather than the item the supplier actually furnished. The claim is billed with the HCPCS code for the non-upgraded item with the charge of that item and modifier GL.

      Item 19 of the CMS-1500 form, or the electronic equivalent, must contain the make and model of the item actually furnished and describe why it is an upgrade.”

  42. blank

    I have a question on the correct modifiers to use in the following instance. We are a DME provider. We have a customer that wants a lift chair which is a face to face item. We have notes from the doctor but they are about a week past the 6 month prior to DOS requirement. In the notes there is only mention of Osteoarthritis and the CMN has a DX of osteoarthritis. For these reasons we had the patient sign an ABN. I was wondering what modifiers we would use to show that we have the notes and we expect it to be denied and have a signed ABN?

  43. blank

    On November 1, 2015 Medicare no longer allows the GA and AT modifiers to be used together. Do you have any ideas about how to bill a service as acute and let them know that we have an ABN on file? When talking with Medicare reps, they don’t have a clue.

  44. blank

    Hi Manny,
    I am trying to find out if GA is the correct modifier that we would use for hearing aids since Medicare doesn’t cover those services at all?
    Thanks, Michelle

  45. blank
    Melinda Woodard

    Hello, I work at a hospital and we are having difficulty understanding which modifier(s) to use on physical therapy services. Our physical therapy department indicates that the services do not meet medical necessity. An ABN was issued. We billed with Occur code 32 and GA modifier on the claim, and Medicare paid (perhaps because of the physician’s diagnosis). We have contacted Medicare and still unclear as to what modifier(s) to use. The ABN option #1 was chosen by the patient, wanting us to bill Medicare for services. Should we use GA, or GX, or both? Thanks

      1. blank

        Perhaps it would be helpful to know that the therapist states the patient does not meet med necessity for services provided by a skiled therapist. In other words they could have it done at a gym, ymca, at their home.

  46. blank

    Hi Manny,

    How can I get the correct PR denial from Medicare for patients that are in LTC to bill the secondary? What modifiers are needed for DME Wheelchairs such as E1161’s?

  47. blank

    Hi Manny,

    We’re needing some clarification on when it’s okay to add a GY modifier. We have a member that doesn’t meet the criteria to get a Lymphadema Pump due to the diagnosis were using yet the doctor wants him to use one. His sec will pay if we get the denial code of PR-204 non covered. The secondary ins will not pay with if we get denial reasons PR-50 & PR-96. If we bill with a GY modifier we’ll we get the appropriate denial code PR-204, but in this case is it okay to bill with a GY modifier when Medicare will cover this item if the member meets the criteria? Do we have to get an ABN on file when we use GY modifier? If we have an ABN on file do we have to bill with Modifier GA? When we add GA modifier we get denied with PR-50 or PR-96. How can we get the appropriate denial of PR-204 that the secondary insurance is asking for? Your help in this matter is greatly appreciated!

  48. blank

    Hi Manny,
    I need to produce a denial from Medicare showing PR, patient responsibility instead of CO, contractual obligation. If I attach the GY modifier, will this cause a PR denial for me to forward to their secondary? Any help will be appreciated.

  49. blank

    Hi Manny, I have several patients that are coming in for a Complete Physical with their PCP; they have Original Medicare A/B; they have been informed that Medicare does not cover this service (code #99397); they say they have checked with their secondary insurance and a physical will be covered and they are willing to sign an ABN. Just making sure which G code modifier is correct for the physician to bill in these cases. It looks like GX would be the appropriate one, but want to make sure. Thank you for your help.

    1. blank

      Karen — Adding the GX modifier to 99397 when a Medicare patient fills out a voluntary ABN for this service is correct.

      But keep in mind that even if you forget to obtain an ABN or the patient does not fill out the ABN properly, you can still bill the patient for the physical since it is not covered by statute.

      We have billed many a Medicare patient that had a 99397 performed and there was no ABN on file and collected. That said, the best practice is to inform your patient so they know ahead of time that they may be billed for the physical.

      1. blank

        What is the 99397 code for Physical. I was always under the impression that E/M 99202-99204 (99212-99214) are not covered. At least I use these codes for E/M. Should I be using 99397 for Medicare. We don’t use GY, I add a -25 to the code and charge the patient $25 for an exam to make it affordable for them.

        Thank you for your reply, I like your explanations to the question from other folks. Appreciate it.

        1. blank

          Hi Niraj –

          Medicare does not cover routine physical exams such as the 99397 or 99387. Medicare will never pay those two codes. Medicare does cover problem orient E/M visits 99201-99205 and 99211-99215.

          The GY modifier is used to obtain a denial on a Medicare non-covered service. This modifier is used to notify Medicare that you know this service is excluded. The explanation of benefits the patient get will be clear that the service was not covered and that the patient is responsible. You can collect money from the patient for these services.

          A modifier 25 indicates to insurance that a significant, separately identifiable E/M service by the same physician on the same day of the procedure or other service was done. Usually, you would use this code on an E/m visit when a procedure was done to show the two separate items.

          Hope this helps.

  50. blank

    We are not participating in the Medicare program, do to the fact that the equipment we provide is not in Medicare’s fee schedule. But we need the correct denial stating not covered service. Some articles say we must use GZ and some say GA and others GX, or GY. So confused at this point just need the correct denial for Medicaid to cover any idea’s. We need the process to go smoothly and we are small enough that we will be billing on paper which will make the time span seem like forever. Please Advise!!! Thank

  51. blank

    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

  52. blank

    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

  53. blank

    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

    1. blank

      As United State’s leading medical transcription service provider, our competitive outsourced model assists your organization by achieving bottom-line documentation cost savings associated with transcription and document delivery, complemented with increased organization productivity via an integrated dictation, and electronic document management solution.

      1. blank

        achieving bottom-line documentation cost savings associated with transcription and document delivery, complemented with increased organization productivity via an integrated dictation, and electronic document management solution

      2. blank

        your organization by achieving bottom-line documentation cost savings associated with transcription and document delivery, complemented with increased organization productivity via an integrated dictation, and electronic document management solution

  54. Pingback: G Modifiers: Upgrading or Gaming Up the System? - Medical Billing and Coding Certification

  55. Pingback: Medicare Billing for Well Woman Exam Using Codes G0101 Q0091 : Medical Billing Company: Capture Billing

  56. Pingback: Medicare Hospice Modifiers GV and GW : Medical Billing Company : Capture Billing

Learn how to outsource your Medical Billing today

CALL NOW 703-327-1800

Client Testimonials

Bob Laird

I would recommend Capture Billing to anyone who needs a billing company they can trust.

Bob Laird

Steve Rex
Family Practice

In a six-month period Capture Billing increased our Practice’s income by over $100,000.


Julie Reed-Humeniuk
Family Practice

Capture Billing goes over and beyond the call of duty for clients to maximize reimbursement.

Scroll to Top