CPT modifier used for distinct procedural service. Under certain circumstances, the physician may need to indicate that a procedure or service was distinct or independent from other services performed on the same day. Modifier -59 is used to identify procedures/services that are not normally reported together but are appropriate under the circumstances. This may represent a different session or patient encounter, 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 physician. 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.