New Changes De-Spookify Modifier -59

By Donna D. Wilson, RHIA, CCS, CCDS, CPHM

The proper application of modifier -59 (Distinct Procedural Service) has mystified many a coder. The Centers for Medicare and Medicaid Services (CMS) has recently indicated that modifier -59 is the most commonly used and abused of all the modifiers—mainly due to the fact that it is used to bypass edits.

Coders need not be haunted by thoughts of these new HCPCS modifiers. In an effort to decrease incorrect modifier usage, CMS has issued Transmittal 1422/Change Request 8862 effective with dates of service on or after January 1, 2015:

According to CMS the primary issue associated with modifier -59 is that it is defined for use in a wide variety of circumstances to identify:

  • Different encounters (used infrequently and usually correct)
  • Different anatomic sites (less commonly used and problematic)
  • Different services (most commonly used and frequently incorrect).

CMS believes that by adding more precise coding options the number of errors will be reduced. With that in mind, CMS has added four new HCPCS modifiers, commonly referred to as -X {EPSU}, to define subsets of Distinct Procedural Services (modifier -59):

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

“CMS will continue to recognize modifier-59 in many instances, but may selectively require a more specific -X {EPSU} modifier for billing certain codes at high risk for incorrect billing. For example, a particular NCCI (National Correct Coding Initiative) PTP (procedure-to-procedure) code pair may be identified as payable only with the –XE Separate Encounter modifier, but not with modifier -59 or other -X {EPSU} modifiers. The -X {EPSU} modifiers are more selective versions of modifier -59, so it would be incorrect to include both modifiers on the same line.”


Donna D. Wilson ( is a senior director at Compliance Concepts, Inc.

Original source:
Wilson, Donna D. "New Changes De-Spookify Modifier -59" (Journal of AHIMA website), October 30, 2014.