New Distinct Procedural Modifiers

September 10, 2014

By Jessica Jankowski, Executive Client Administrator, Vachette Pathology

We all know or understand the basic idea of The Medicare National Correct Coding Initiative (NCCI), which establishes edits that are used to bundle service codes together.  The basis for this is to outline certain billing codes that cannot be billed with other codes, indicating codes that further define some portion of the first code.

The modifier -59 has always been a go-to modifier to indicate a second service code is indeed distinctly different or separate from the first service code. Per CMS’ recent MLN Matters published January 2014, this modifier “can be broadly applied,” and CMS believes that some providers will use this modifier “to bypass NCCI,” thus allowing for abuse and “high levels of manual audit activity” (MLN Matters Articles, 2014).

CMS is correct in their statement.  The -59 modifier has a broad realm for use, and can be used to identify different encounters, different anatomic sites, and distinct services.  Per CMS, the -59 modifier is seldom used properly, and therefore CMS will bring into play four new modifiers that will further define or describe the -59 modifier.  These will further be known as the –X modifiers (MLN Matters Articles, 2014).  The modifiers and their descriptions are listed below:

  • 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.

According to the MLN Matters, these modifiers will be used in place of -59 when appropriate.  Furthermore, CMS will still identify the -59 modifier when used; however, it is important to note that it is of great importance to use a more descriptive modifier when there is one available.  We may even see CMS require these –X modifiers on specific CPTs that they feel are at a higher risk for incorrect modifier usage.

Bottom line:  Understand these new modifiers and how they are used, and make sure your biller is aware of these and using them when appropriate.


MLN Matters Articles. (2014, 01). Retrieved 09 2014, from The Centers for Medicare and Medicaid Services :


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