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Medicare Modifiers XE, XP, XS, XU: Examples of When to Bill Each One

Examples of of when to use Medicare XE, XP, XS and XU modifiers

Effective January 1, 2015, CMS officially rolled out four HCPCS modifiers, XE, XP XS and XU, that can be used when billing Medicare claims. Dubbed the –X{EPSU} subset, they may or may not be used instead of modifier 59.

Not very clear, right? Unfortunately, there hasn’t been much clarification from CMS about the modifiers either, leaving many physicians and medical practices confused.

So, today I’ll focus on a few examples of when you might use each of these new modifiers. And if you need more background information about why this code subset was created in the first place, this post explains that in detail.

But first, a review of the definitions.

  • Modifier XE Separate encounter – A service that is distinct because it occurred during a separate encounter.
  • Modifier XP Separate practitioner – A service that is distinct because it was performed by a different practitioner.
  • Modifier XS Separate structure – A service that is distinct because it was performed on a separate organ/structure.
  • Modifier XU Unusual non-overlapping service – The use of a service that is distinct because it does not overlap usual components of the main service.

When to Use Modifiers XE, XP, XS, XU

The following are potential scenarios is which the new Medicare modifiers might be used.

ScenariosModifierReasoning & Notes
Surgery operative sessions: One surgery procedure at 9AM and one at 6PM.
Physical therapy sessions: Group therapy services (97150) at 10AM and therapeutic exercises (97110) at 4PM. 
  • Separate encounters.
  • Same date of service.


Patient is seen by her OB-GYN. During the exam, the doctor notes an issue and requests his partner, a perinatologist, examine the patient as well.
Patient is under treatment for breast cancer. During her appointment, she is seen by two physicians in the practice – the medical oncologist and the radiation oncologist.
  • Separate practitioners.
  • Same date of service.
  • May or may not be the same encounter.
  • May or may not be different specialties.
  • Both practitioners fall under same TIN.


Injection into tendon sheath, elbow (20550) and injection into tendon sheath, knee (20550-XS).XS
  • Separate structure or organ.
  • Different anatomical site.
  • Same encounter.
A diagnostic procedure is performed. Based on the findings, a therapeutic and/or surgical procedure is required on the same day. For example, diagnostic cardiac catheterization is followed by a medically necessary cardiac procedure.XU
  • Same encounter.
  • Same practitioner.
  • Same anatomical site, structure, or organ.

Remember that you’ll never use modifier 59 in conjunction with one of the X{EPSU} modifiers. They are designed to be used separately – it’s either one or the other.

Which, of course, makes this all the more confusing. Watch for CMS to provide further clarification and examples in 2015. And don’t be surprised when other payers begin requiring the more specific modifiers too, since they usually follow CMS’ lead.

Additional Resources

Medicare Learning Network: MLM MM8863

Manual System: Transmittal 1422

Also check out my other post on these X{EPSU} modifiers.

Do you have more scenarios that may help other billers and coders? Please share them in the comment section below.

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75 thoughts on “Medicare Modifiers XE, XP, XS, XU: Examples of When to Bill Each One”

  1. blank

    Manny, I have a claim where procedure code 17262 was used due to destruction of skin lesions in 2 different anatomical sites, and at the same time as other procedures. (MOHS lesion and repair of defect). Modifier -59 was used on all 5 lines of the claim as follows:
    Line 5 has been denied as incidental to the primary. Would it be appropriate to use modifier -59 to line 4 and SX to line 5?
    Thank you~

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    I do coding for anesthesia. My question is when they do a postoperative pain block, we have been using, for example 64415-59-Lt with 76942-26 (US guidance), should we be using the XE instead of 59 modifier?

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    I’m a biller for Prosthetic & Orthotics, we have a patient that needs daytime and nighttime orthoses. We billed L1945 RT/LT KX & L1970 RT/LT KX 59. We keep getting denying I thought I finally had it right but denied again! Any suggestions

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    i am new to rheumatology coding and i am trying to correct someone’s error (that person has retired now). i thought claim should look something like – i am just backup but everyone seems to be looking to me for the answer
    Thank you

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    I’m wondering about your choice of including both the XS and 59 modifier on the same line? My first thoughts are to use the XS OR the 59, but not both.

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    for trigger point injection into right thumb and right 3rd finger; can i bill
    thank you

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    I am new to ortho billing. What is the correct billing for procedure code for 99214 w/24 25 modifier, q4177, 20610 79/LT modifier and 97597. Patient also, had a procedure done back in Jan for procedure 27447. the patient will still be in her 90 day global. So 97597 probably will not be payable.

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    Hi, I’m new to orthopedic coding. I am billing the following codes to Medicare and need to know which X modifier would be appropriate….I am thinking XU


    Sorry but my employer has yet to purchase a coding software.


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    I work in a Chiropractic office and we have been billing to Triwest and getting denials for service 97110. I have tried every single possible modifier combination with no luck. The services are authorized but continue to be denied.Any help is appreciated.

  10. blank

    I am trying to bill 88305. here is the issue. the Dr. sent specimen to 2 different labs, reviewing 2 different areas to 2 different Drs. All of our claims are being denied while the other dr. is being paid. How do we bill to ensure payment?

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    We have issued with Aetna insurance for code E/M code when we billed with 25 modifier. Patient visited as Obesity.

    CPT codes 99213-25 96372 G0447 99070 J3420 – Insurance processed all the codes except code 99213 – 25

    Kindly advise which modifier should we take in order to get payment for code 99213.


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      You might need to check your contract as this is not a new patient E/M. There might be rules stating you can not bill that code within 90 days unless the exam is for something totally different than the last E/M visit and the diagnosis shows it. I know some insurance companies have their own rules about E/M codes.

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    Does anyone know where I can obtain specific CMS Guidelines on the use of the X Modifers in Laboratory and Pathology.
    For example; use of multi CPT codes on same day same physician 85390,85396, 86255 and then with different physician, Different Group, same DOS. Also, Pathology CPT: 88342, 88341, 88377 same DOS, same Physician and different physician, different group, Same DOS.
    Thank you

  13. blank

    I bill for Podiatry services. I have been having issues with Aetna and Aetna’s Coventry MCR ADV products since the beginning of 2019. When we bill
    11056 E11.59 L85.1 and
    11721 59 E11.59 B35.1
    Aetna is paying for the 11056 but paying nothing for the 11721 service stating that it is bundling the 11721 into the payment for 11056. They also bundle 97597 when billed with 11056 59 and 11721 59, paying only for the 97597 and denying payment for 11056 and 11721. I tried calling to have the claim reprocessed but was told I need to do an appeal. My question is should I be using a XS modifier rather than a 59 modifier? Any guidance would be appreciated.

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    Patient has a multi-day test but Day 1 the test doesn’t start until after midnight when the patient falls asleep and then Day 2 the patient falls asleep at 10pm- Both Dos are technically the same since the DOS is when the test starts from what Jennifer has told me. So what modifier gets added to what day so that we are telling the payers that these are the same code, but actually separate tests due to the start dates?

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    I am a dermatology biller and often bill the following codes together to Medicare:
    17000 -51 icd L57.0
    17003 icd L57.0
    88305-26 icd D48.5
    11102-59 icd D48.5
    11641-59 icd C44.321
    99213-25 icd L85.3

    Where would I put the XS modifier if it is more accurate?

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    For outpatient therapy services when a patient receives PT, OT and Speech evaluations (or maybe just 2 disciplines) on the same day should we use modifier XP or 59 ?

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    Hi, We are trying to bill 73560-59 and Arthrogram 73580-LT/RT on the same day. Arthrogram will be used for supplementation hyaluronic acid knee injection procedure. X-ray is for findings and Arthrogram is for the procedure. Humana Medicare replacement is denying xray code. Should we bill x-ray with XU modifer instead? Please guide.

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    Question: pt receiving ommaya treatment 96542 via reservoir and avastin infusion via infusion pump PAC right chest in the same encounter. would the XS modifier be appended to both 96413 and 96542?

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    Hi, What about when you are billing for Ultrasound Extremities. We have been getting denial on this code when using Modifier 59 and 76. (denial reason is payer deems the information submitted does not support this many frequencies.

    Would this be the correct way to send to get paid for all 4 charges? Thanks

    76881 LT DX: M79641
    76881 RT,XS DX: M79642
    76881 LT DX: M25511
    76881 Rt,XS DX: M25512

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    Hello, can we use modifier XU and 79 together? i.e. 20550-XU,79. This procedure was performed within a global period and there was another procedure performed on the same day (20680-58). Thanks

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    Excision of a tumor (27339) is included in a total knee arthroplasty (27447), would it be appropriate to use the -XU modifier on the 27339 if it was done in the same knee at the same time? Excising a tumor is not a “usual” component of the TKR because not everyone that gets a knee replacement has a tumor in their knee. The definition of the -XU is a little confusing to me. Thank you in advance for any help you can provide.

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      Hi Jennifer!

      There is a direct CCI edit for these two codes together but a modifier is allowed to override this relationship. -XU could certainly apply to this situation, in lieu of the broader -59 modifier. Documentation and a cover letter would also be vital to getting your claim paid.

      Based on instructions from WPS:

      Appropriate Usage

      Coding pairs are part of the National Correct Coding Initiative (NCCI) procedure to procedure edits Documentation indicates the service was not part of the usual components of the main service Use Modifier XU with the Column 2 procedure code in the NCCI files Use Modifier XU only when there is no other modifier to describe the situation.

      Make sure you check with your local Medicare carrier on their billing procedures for your situation.

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    I have question. The G0444( DEPRESSION SCREEN) AND G0102, are getting denied (co45)when we bill as follows:
    G0439- Z00.00
    G0444- Z13.89
    G0102- Z12.5
    99213-25 (PHARYNGITS, COUGH)
    Should I be using a modifier? according to the Medicare website their allowed one. Are the G0444/G0102 not payable but bundled into the G0439? From what I have read they allow 1 per calendar year.Confused??

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    For family practice,

    If your billing an office visit 99213(low back pain, ear pain), with other procedures done in the office 69210(cerumen removal), 93000(shortness of breath) 94010 Would I use the XS MODIFER on all the cpt codes except the 99213? Please advise. THIS would be a Medicare age patient who is on CIGNA MEDICARE SELECT. Please advise. Thank you!

    1. blank

      Based on the rules for modifier -XS, this modifier can be used to indicate a “Separate structure, a service that is distinct because it was performed on a separate organ/structure”. However, we typically don’t use that modifier when submitting Medicare claims. In this scenario we might bill out as follows:

      99213-25 with the appropriate diagnosis codes
      69210 with the diagnosis code that supports the medical necessity of this procedure only
      93000-59 with the diagnosis code that supports the medical necessity of this procedure only
      94010-51 with the diagnosis code that supports the medical necessity of this procedure only

      Have you billed out your claim already and was it denied? What modifiers did you use? Did you use only the –XS modifier and nothing else? Would definitely suggest appending -25 to the E/M visit.

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    I am having difficulty billing 65855. I am getting denial from Medicare that the modifier is incorrect on the FIRST eye. What should I be using other than the RT/LT? Also, can we no longer bill for second eye (65855) within the post op period of the first?? If so, what is the proper way? There has been a lot of changes to this Code and I’m just a little confused.

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      Medicare should pay for 65855 using RT or LT. Make sure the DX code matches RT/LT. When billing for the second eye during the 10 day global period use a 79 modifier on your claim to indicate that this procedure is unrelated to the first. No need to use the 79 after the global period.

      As an example a claim may look something like this:

      65855 RT, H40.051
      65855 79 LT, H40.052

      Check with your carrier on their specific billing guidelines.

  26. blank

    When billing fracture care to medicare for metatarsal fractures 2 through 4, is it proper to bill 28470, 28470/xs/LT, 28470/xs/LT?

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    I work for an OB-GYN practice when billing ob ultrasounds for twins we bill the code x2 for each fetus Example: 76815 76815,59 is this correct or should we be now using xs,

  28. blank

    I bill for a plastic surgeon who removed 3 lesions from a patient, 3 different sites, chest, back and leg. procedure code is 11302. I usually bill it with mod 59 on first charge, mod 59,RT on second charge and mod 59,51 on third. I feel XS could be used instead, but do I use it on every charge? where do I note the actual site, if needed at all?

  29. blank

    I code 20550 a lot. Most of the time there’s 2 or 3 different sites that were injected. Can you tell me the appropriate way to use modifier XS, and do I need to use modifier 51 as well?

  30. blank

    thanks for sharing……but i still have a little confusion of using XP modifier though i clear with other modifier….hope this confusion will be clear with more examples of these modifiers…thanks for sharing

  31. blank

    Three questions regarding billing chemotherapy charges:

    When giving hydration due to dehydration when a patient is getting chemotherapy i normally would use -59 on the 96361, should I use -XU. Would -59 be wrong or would both work?

    When giving chemotherapy and an injection is given such as neulasta, I use -59 on the 96372, but should I use -XU? Would -59 be wrong or would both worth?

    Injection is given of atropine which is part of the chemotherapy regimen. I do not put any modifier on the 96372 since it is part of the regimen. Am I creating myself a problem, or should I be using a modifier.

    Thanks for your help!

    1. blank

      We are also wondering if we should use 59 or XU on 96372 (neulasta) when billed with 96413. Has anyone figured out if it is 59 or XU?
      Thanks Diane

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    All insurances pay for smoking sessation consult. Mod 59 must be applied to E&M visit if smoking sessation consult can be identified separately from office visit. Check provider’s notes if this consult documented properly. Also do not link Dx-305.1 or other smoking disorder Dx to E&M, link it only to 99406.
    Your question is not related to X(EPSU) modifiers. Ask questions like this on AAPC forum, and you will get right answer.

  33. blank

    I have tried to bill an office visit, ie 99213, with a 99406, smoking cessation. I put modifier 25 with the 99213 and got denial. I have tried other procedures with office visits using the modifier 25 and they only pay for the one with the lowest charge. What am I doing wrong? Should I use modifier 59 instead? The doctor is doing the e&m and the procedure or smoking counseling, we just need to code it right. Please advise.

    1. blank

      Modifier 25 goes on the 99406. (We have found that modifier 25 goes on office visit for Medicare, while 25 goes on 99406/99407 for all commercial carriers.)

      “When providing a preventive visit with a problem-oriented E/M service or procedural service on the same day, including modifier 25 in your coding may enable you to be paid for both services. CPT says modifier 25 is appropriate when there is a “significant, separately identifiable evaluation and management service by the same physician on the same day.” Stated another way, if the second service requires enough additional work that it could stand on its own as an office visit, use modifier 25. Modifier 25 should usually be attached to the problem-oriented E/M code. However, if the second service is a procedure, such as removal of a skin lesion performed in conjunction with a preventive visit, the modifier should be attached to the preventive visit code because it is the E/M service.”

  34. blank

    What if the Dr. performed a colonoscopy (45378) and also patient had and IV infusion therapy with Remicade (for Crohn’s disease) the same day. Almost never done the same day but necessary. Would I use the XU modifier?

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    I have been receiving denials for the following code combination:
    11721 and 11055 or 11056 Billed as follows:

    11721 59 Q9
    11056 Q9
    11721 Q8
    11056 59 Q9

    Either way the claim is sent it is denied as not separately payable. I didn’t think the XU modifier was appropriate. Can you please tell me if I should use the XU modifier in place of the 59 modifier? I am positive these codes are separately payable…aren’t they? After all, they are two distinctive procedures.

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      I am working for Podiatry for three years. We do not have denials with 11721-59,Q9 and 11056-Q8. Mod 59 applied to 11721, not to 11056.
      The second combination of codes is wrong:1) Mod Q should be the same for both codes; 2)Mod 59 applied for 11721 only in this set of codes, not to 11056.
      Please check office visit notes, the reason of denials is not Mod 59.

  36. blank

    Help please and a new reader to this forum. I like what I’ve seen already! Billing for rheumatology specialist in private practice and codes submitted for a particiar patient’s care:
    20610-LT, 77002 (719.91)
    64418-LT (59 or XU?) 76942 (716.61)
    J code for medication

    Since 64418 bundles into 20610, and the other procedures also bundles into one another( with the exception of the medication, of course), which modifier would be preferable? I’m leaning towards the 59 still, although considering XU. Doctor informed us that he doesn’t generally perform the block with the injection procedure, so that’s why I was wondering about the XU. XS modifier wouldn’t be appropriate since it is performed in the same anatomical area (L. shoulder) and I can’t seem to find any definitive answers regarding my question.

  37. blank

    What if a patient is having snare polypectomy of sigmoid colon and cold biopsy of ascending colon, what modifier would be used ?

    1. blank

      Did you get a response to this question? I am wondering the same thing. At first I was thinking XS, as in separate location. But, the more I read about these codes, I’m thinking about sticking with 59.

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    In your example for XS- the modifier to be reported would be a 50 (bilateral). WPS has done some training on these new modifiers and they have stated that these new modifiers do not apply to MUE edits, but rather CCI edits. They also have firmly stated that if another modifier would apply, not to use the X modifiers.

    Another example – Two separate encounter for drug infusion same day (96365). They have stated that providers should continue to use the 76 modifier, since it is the same CPT code twice in one day.

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    Initial practitioner performs the primary procedure, another physician performs an add-on procedure. Use the XP, separate practitioner modifier. Cardiac procedures are a good example.

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    We are an orthopedic practice and can give a patient more than 1 injection on the same visit. We usually bill 20610 (LT) and 20552 (59). Should we now use modifier XS. Please advise.

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    If there was a nerve block done with a procedure, example: menisectomy with a nerve block, which of the X (EPSU) modifiers would be appropriate to use?

    would it be considered a separate practitioner, structure?

    thank you!

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    Question in Podiatry specialty.
    During visit were performed 10 nails debridement and one callus cutting.
    Can be billed 11055 with 11721-59? Tissue is adjacent.
    Thank you.

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    I have read the following,

    Legislative Alert – Update on Modifier 59

    In response to a direct inquiry by APTA about the changes to Modifier 59, CMS has responded that providers should continue to use the modifier without the new subsets (XE, XS, XP and XU) until they receive further notice.

    Has there been further notice to actually use the new modifiers? I have read the Transmittal 1422 dated August 15, 2014, which says to start using them 1/5/15.

    Could you please advise.
    Thank you.

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    So if a DPM does nails and callouses it usually billed

    11056 Q9
    11721 59 (so we would now use XU)?

    after say an office visit that had a x-ray, injection and strapping of the left foot, the strapping would also get the same XU modifier?

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      Jane I would use a 59 and not a XU. I think a XU modifier would be better used when based on the findings of a diagnostic procedure, a therapeutic and/or surgical procedure is peforemed on the same day.

      Now for part two of your question, I would use a XU modifier here becasue based on your X-ray, a diagnostic procedure, you performed a therapeutic procedure, injection and strapping of the left foot, which in my opinion qualifies for a XU to be added.

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            What if the corns or calluses are on the toes and not foot. Would the most appropriate modifier be XS or 59 for 11056 Q9, 11721 Q9.

            Do you have to do a diagnostic procedure such as an X-ray before using XU modifer on strapping performed with injecion and E&M.

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