Medicare’s New Ruling for Modifier 59 – Medical Billing Modifiers

Change is coming on January 1st 2015 and the focus will be procedure modifier 59 – the modifier that is used to define Distinct Procedural Services. It is one of the most commonly used, as well as misused and abused modifiers. Because of the misuse, CMS plans to eliminate the confusion and created specific modifiers to define services. Many coders use modifier 59 in order to bypass the National Correct Coding Initiative (NCCI) edits and in many cases, this unbundling is wrong. When coders use modifier 59, they should use it to identify one distinct service from another on the same date of service. It is also supposed to be used to identify different anatomical sites when a procedure is being performed.

Lastly, it is used to identify different encounters. According to CMS, coders seem to have a significant problem identifying the different anatomical sites over other coding issues causing Medicare to lose over $750 million dollars due to improper usage of modifier 59.

On August 15, 2014, CMS Medicare released a notification titled: Specific Modifiers for Distinct Procedural Services. This notification introduces four (4) new HCPCs modifiers designed specifically for modifier 59 use and eliminate the confusion that coders face. Since the definition of modifier 59 is so expansive, the introduction of CMS’s four (4) new HCPCs modifiers will assist the coders in choosing a more appropriate Medical Billing Modifiers, reducing the errors linked to overpayments made by CMS.

Medicare’s New Ruling for Modifier 59 – Medical Billing Modifiers

Let’s take a look at the newly created HCPCs modifiers:

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 healthcare provider
XU: Unusual Non-Overlapping – The use of a service that is distinct because it does not overlap usual components of the main service


When coding with modifier 59 or the -X HCPCs modifiers, be aware that you cannot use both modifier types on the same line with a procedure. Although CMS will continue to recognize modifier 59 in many instances, they are expecting you to assess the documentation and choose the modifier appropriately – whether it be modifier 59 or one of the X modifiers. CMS indicates that these new modifiers are valid even before national edits are imposed. It is important for coders to read all CMS releases from their state regarding these modifiers since different contractors are used throughout the country. Modifier 59 has been monitored for years due to the problems associated with it, so I highly recommend that you stay on top of the changes coming in January 2015. It is your responsibility; and you will be liable should you not follow the guidelines.

The first quarter of 2015 will demonstrate how easily these new HCPCs modifiers transition and pay. Many of us know through experience, that coding changes do not always flow as easily as we would like them to, so proper attention should be given during this first quarter. In addition to this, coders should devise a cheat sheet of the local carriers their practice is affiliated with, and document how and when the local payers adopt the new X modifiers.

For more information on the changes with modifier 59, you can link to:

Read more about Medical Billing Modifiers

Medical Coding – Use of Modifier 59 – Video

AAPC  – Modifier 59 and Medicare

medical billing modifiers

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