Modifier 59 is referred to by CMS as the modifier of last resort. It is often used when modifier 51 is the more accurate modifier. This quick reference sheet explains when, why and how to use it.

In addition, you will find tips related to:

• A process to determine if modifier 59 can be used
• Performed the same procedure twice in a single day
• E/M and some HCPCS codes for Medicare
• CMS developed HCPCS modifiers-X {EPSU} but never implemented them nationally (some MACs use them)

From CPT^®:

Distinct Procedural Service: Under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-E/M services performed on the same day. Modifier 59 is used to identify procedures/services, other than E/M services, that are not normally reported together, but are appropriate under the circumstances.

Documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. However, when another already established modifier is appropriate it should be used rather than modifier 59. Only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used.

Note: Modifier 59 should not be appended to an E/M service. To report a separate and distinct E/M service with a non-E/M service performed on the same date, see modifier 25.

Other modifier resources

• Using Modifier 25 | Quick Reference
• Using Modifier 33 | Quick Reference
• Modifiers in Primary Care
• Other modifiers