White Papers

CMS Introduces 4 New Modifier Choices to Use Instead of -59

Modifier 59 (Distinct Procedural Service) is described by the Centers for Medicare and Medicaid Services (CMS) as the most widely used HCPCS modifier.  In its August 15, 2014 Transmittal R1422, CMS contends that there are three common reasons that modifier 59 is used:

• Identify a separate session or encounter
• Define a separate anatomic site
• Indicate a distinct service

This modifier is charged with being used most-frequently to override the National Correct Coding Initiative’s bundling edits which CMS contends are often done incorrectly.  In an effort to reduce associated errors and improve billing patterns, CMS is presenting four new ‘subset’ modifiers effective January 1, 2015.

  • 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 accept modifier 59 in 2015 but is encouraging providers to begin utilizing these more selective “X(EPSU)” modifiers in its place when appropriate.  Ultimately, it is expected that CMS will develop national edits around these new modifiers; however, local Medicare contractors (MACS) can establish their own requirements for the use of these modifiers as well as 59.

It is unknown at this time if commercial insurance carriers will accept the new X(EPSU) modifiers come January.  APS will continue to monitor industry guidance and provide updates as they become available.

Recent White Papers

Q3 2020 CPT Codes Included in the Laboratory Date of Service Exception Policy for Designated ADLTs & Molecular Pathology Tests
July 15th, 2020
United Healthcare Exerts Downward Pressure on Lab Reimbursement
July 10th, 2020
Updates in Surprise Bill Legislation
July 01st, 2020
DHCS CA Medi-Cal Responds to Novel COVID-19
July 01st, 2020


The APS team constantly updates and educates us on any new changes in billing/coding that are happening or will be happening.

Mountain View, CA

Are you ready to start seeing increased revenues? APS’ expertise and commitment to service can get you there.
Begin your partnership with APS Medical Billing.
Contact Us