The Centers for Medicare & Medicaid Services (CMS) in 2015 established four HCPCS modifiers to define subsets of modifier 59 (distinct procedural service). The modifiers are: XE, XS, XP, and XU, commonly noted in payer policies as X{ESPU} modifiers. Modifier 59 is intended to indicate a separate and distinct service from another service with which it is usually bundled. This modifier is often used incorrectly to bypass Medicare National Correct Coding Initiative (NCCI) edits. For this reason, modifier 59 is frequently audited.¹

How is modifier 59 defined in CPT?

CPT states, “Modifier 59 is used to identify procedures or services, other than E/M services, that are not normally reported together but are appropriate under the circumstances. Documentation must support a different session, different procedure or surgery, different site or organ system, separate incision or excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual.”

It is very important to note that a unique diagnosis for the service is not sufficient reason to apply modifier 59 or one of the X modifiers. Each of the subset modifiers identifies a specific type of distinct procedural service based on site, session, provider, or non-overlapping service.

• XE Separate Encounter. A service that is distinct because it occurred during a separate encounter (think E for encounter). A separate encounter involves a separate visit or session on the same day by the same provider or providers of the same group.
• XS Separate Structure. A service that is distinct because it was performed on a separate organ/structure (think S for structure). Medicare defines a different anatomic site as: “…includes different organs or different lesions in the same organ. However, it does not include treatment of contiguous structures of the same organ. ... Treatment of posterior segment structures in the eye constitute a single anatomic site.” Different portions of the retina or different areas of the eyelid do not constitute a different structure.
• XP Separate Practitioner. A service that is distinct because it was performed by a different practitioner (think P for practitioner). This modifier applies when providers in the same group are involved in the care of a single patient.
• XU Unusual non-overlapping service. The use of a service that is distinct because it does not overlap usual components of the main service (think U for unusual). NCCI instructs, “A biopsy performed at the time of another more extensive procedure (e.g., excision, destruction, removal) is separately reportable under specific circumstances. If the biopsy is performed on the same lesion on which a more extensive procedure is performed, it is separately reportable only if the biopsy is utilized for immediate pathologic diagnosis prior to the more extensive procedure, and the decision to proceed with the more extensive procedure is based on the diagnosis established by the pathologic examination.”

When are the X {EPSU} modifiers used?

While modifier -59 will still be accepted, providers are advised to use a more specific X modifier if appropriate.² Either 59 or the appropriate X modifier is used in circumstances in which the NCCI edits, or the CPT “separate procedure” rule should not apply, and separate reimbursement is justified by Medicare’s instructions and criteria.³

When are the X {EPSU} modifiers not used?

Like modifier -59, the X modifiers should not be used simply to circumvent CPT’s “separate procedure” rule or the NCCI edits. The requirements described above in application of these modifiers must be satisfied.

Conclusion

The subset X modifiers help clarify the circumstances in which it is acceptable to separately bill services that are otherwise affected by NCCI edits and the “separate procedure” rule in CPT. Although some MACs have been slow to publish information on the use of these modifiers, CMS has resources available in the CMS Manual and the recent MedLearn Matters Article. GP

References

1. CMS Transmittal 1422, Specific Modifiers for Distinct Procedural Services. August 15, 2014. Available online: http://www.cms.gov/Regulations-and-Guidance/Guidance/Transmittals/Downloads/R1422OTN.pdf . Last accessed August 11, 2017.
2. Moda Health Reimbursement Policy. October 8, 2014. Available online: https://www.modahealth.com/pdfs/reimburse/RPM027.pdf . Last accessed August 11, 2017.
3. National Correct Coding Initiative Coding Policy Manual for Medicare Services, Chapter 1. Centers for Medicare & Medicaid Services website. Available online: https://www.cms.gov/Medicare/Coding/NationalCorrectCodInitEd/index.html?redirect=/NationalCorrectCodInitEd/ . Last accessed August 11, 2017.

Kevin J. Corcoran, COE, CPC, CPMA, FNAO, is president and co-owner of Corcoran Consulting Group.