Skip to Main Content

Modifier -59

Provider Type

  • Physicians

Counties Covered

  • Fresno
  • Kern  
  • Kings
  • Los Angeles
  • Madera
  • Sacramento
  • San Diego 
  • San Joaquin
  • Stanislaus
  • Tulare

The American Medical Association (AMA) CPT definition of modifier -59, distinct procedural service, is as follows: "Under certain circumstances, the provider 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 participating provider. However, when another already established modifier is appropriate it should be used rather than modifier -59. Only if a more descriptive modifier is not available, and the use of modifier -59 best explains the circumstances, should the modifier -59 be used."

Use modifier -59 with the code that would normally be considered a component of a more comprehensive procedure when the procedures are distinct (as defined by the CPT definition of the modifier set forth above). The medical record must reflect that the modifier is being used appropriately.

Health Net reimburses separately for procedures billed with modifier -59 as permitted by AMA CPT guidelines and national CMS policies such as the Correct Coding Initiative (CCI) edits and the bundled services policy.

The following policy is an exception to this rule. In this case, the service billed with modifier -59 would not qualify for separate reimbursement:

  • Pulmonary perfusion imaging is included with myocardial perfusion studies when both are performed at the same time

Claims should be coded with ICD-10-CM codes corresponding to all procedures billed. This serves to further support the distinctness for some types of procedures.

Modifier -59 should not be used if one of the following modifiers is more descriptive than modifier -59.

  • E1-E4 (eyelid)
  • FA (left thumb)
  • F1-F9 (fingers)
  • LC (left circumflex coronary artery)
  • LD (left anterior descending coronary artery)
  • LT (left side)
  • RC (right coronary artery)
  • RT (right side)
  • TA (left great toe)
  • T1-T9 (toes)
  • 50 (bilateral procedure)
  • 58 (staged procedure)
  • 78 (return to the operating room)
  • 79 (unrelated procedure by different physician during postoperative period)
  • 91 (repeat clinical diagnostic laboratory test)
  • XE (separate encounter, a service that is distinct because it occurred during a separate encounter)
  • XP (separate practitioner, a service that is distinct because it was performed by a different practitioner)
  • XS (separate structure, a service that is distinct because it was performed on a separate organ/structure)
  • XU (unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service)

Health Net does not require documentation for modifier -59 at the time of claim submission; however, in the event the claim is audited, documentation may be required.

Refer to the National Correct Coding Initiative (NCCI) Edits and Unbundling and Fragmentation policy for more information.

Prepayment Clinical Claims Review

Health Net conducts prepayment clinical claims reviews on all procedures billed with modifier -59. A Health Net registered nurse reviews the information billed on the claim, along with the member's and provider's claims history, to determine whether modifier -59 was used correctly for procedures performed on the date of service. Health Net uses nationally published guidelines from CPT and CMS when determining whether the modifier was used correctly, including the use of claim documentation requirements as listed below:

  • The diagnosis codes on the claim indicate multiple conditions or sites were treated or are likely to be treated.
  • Claim history for the patient indicates that diagnostic testing was performed on multiple body sites or areas, which would result in procedures being performed on multiple body areas and sites.
  • To avoid incorrect denials providers should assign to the claim all applicable diagnosis and procedure codes using all applicable anatomical modifiers designating which areas of the body were treated.

Provider Appeals and Dispute Resolution Requests

In the event the claims documentation is insufficient to support billing modifier -59, Health Net will send the provider denial determination on his or her explanation of payment (EOP). The provider may submit an appeal or reconsideration request according to the guidelines outlined in the provider operations manual under Dispute Submission. Providers should submit all pertinent medical records for the date of service and procedures billed. Medical records should not be submitted on first-time claims submissions as first-time claim reviews consist only of a review of the information documented on the claim and in the member and provider history. Medical records should only be submitted once the provider receives a denial and wishes to request a reconsideration or appeal.

Supporting Sources

  • AMA CPT
  • CMS National Policy
Last Updated: 10/30/2019