Eventually, four new modifiers will completely replace -59.
Modifier -59 was replaced on January 1, 2015 with more defined subsets. The four new modifiers are (XE, XS, XP and XU). The shift to the more detailed modifiers occurred in order to allow more specific information about the encounter to be reported on the claim form by hospitals and physicians. However, immediately after the change, requirements to use the new modifiers were delayed per CMS MLN Matters SE1503. Providers now have the option of using -59 or submitting the new modifiers until CMS makes it mandatory.
Modifier -59 is appended to a CPT code when providers perform a separate and distinct procedural service on the patient on the same day as another procedural service that is not an evaluation and management service. It allows providers to bypass National Correct Coding Initiative edits that normally block a separate payment, which means that the modifier can generate additional reimbursement.
Modifier -59 and the new modifiers are basically synonymous for now. Eventually, when the change is made, the four new modifiers will completely replace -59. The descriptions of each are as follows:
- 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 providers have an option on which modifier to use, more guidance is needed from CMS based upon the types of clinical scenarios so that there is consistent implementation. Providers need to keep track of future CMS publications about the issue but should assess how -59 is currently used in their documentation and billing process to best prepare for the change once it is finalized.