Medicare Introduces New Modifier Subsets for -59-

The Centers for Medicare & Medicaid Services (CMS) is establishing four new Healthcare Common Procedure Coding System (HCPCS) modifiers to define subsets of the -59- modifier, which is used to designate a “distinct procedural service.”

Modifier 59 is the most widely used HCPCS modifier: It is defined for use in a wide variety of circumstances, and is often applied incorrectly to bypass National Correct Coding Initiative (NCCI) edits. This modifier is associated with considerable misuse and high levels of manual audit activity, leading to reviews, appeals, and even civil fraud and abuse cases. The introduction of subset modifiers is designed to reduce improper use of modifier 59 and help to improve claims processing for providers.

Transmittal 1422, Change Request 8863 provides that CMS is establishing the following new modifiers—referred to collectively as -X{EPSU} modifiers—to define specific subsets of the -59 modifier:


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
Although CMS will continue to recognize modifier 59 in many instances, per CR8863:
CPT instructions state that the -59 modifier should not be used when a more descriptive modifier is available. CMS … may selectively require a more specific – X{EPSU} modifier for billing certain codes at high risk for incorrect billing. For example, a particular NCCI PTP code pair may be identified as payable only with the -XE separate encounter modifier but not the -59 or other -X{EPSU} modifiers. The -X{EPSU} modifiers are more selective versions of the -59 modifier so it would be incorrect to include both modifiers on the same line.
The implementation date for this change is Jan. 5, 2015. Initially, either modifier 59 or a more selective –X{EPSU} modifier will be accepted, although CMS has encouraged a rapid migration of providers to the more selective modifiers. For further instructions regarding this change check with your MAC.