Modifier -59 is used to define a "Distinct Procedural Service" to indicate that a reported code represents a service that is separate and distinct from another service with which it would usually be bundled. The -59 modifier is the most widely used HCPCS modifier and is associated with considerable abuse and high levels of manual audit activity, leading to reviews, appeals, and civil fraud and abuse cases.

The primary issue associated with the -59 modifier is that it is defined for use in a wide variety of circumstances, such as to identify different encounters, different anatomic sites, and distinct services. This modifier is infrequently (and usually correctly) used to identify a separate encounter. It is less commonly (and less correctly) used to define a separate anatomic site. It is more commonly (and frequently incorrectly) used to define a distinct service.

CMS established four additional HCPCS modifiers (called -X{EPSU}) to define specific subsets of the -59 modifier:

While CMS recognizes the -59 modifier in many instances, it 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.

These modifiers were developed to provide greater reporting specificity in situations where modifier -59 was previously reported and may be utilized in lieu of modifier 59 whenever possible. Modifier -59 should only be utilized if no other more specific modifier is appropriate.

Although NCCI will eventually require use of these modifiers rather than modifier.

Source: MAB