At A Glance

  • Knowledge of bundled codes, global periods, and the differences among insurance carriers’ policies can lead to receiving successful reimbursement.
  • The author provides an overview of each of those key principles to help you master retina coding and optimize your practice’s reimbursement.

Accurate coding can reduce denials and ensure prompt and proper payment for services provided. Knowledge of key coding principles will contribute to successful reimbursement. This article presents an overview of a few of these key principles.


National Correct Coding Initiative (NCCI) edits are published periodically by CMS. NCCI edits bundle specific CPT codes when the procedures are performed by the same surgeon or group practice, in the same patient session, or at the same surgical site.

CMS publishes quarterly NCCI edits to identify CPT codes that are considered bundled (not separately payable) when performed on the same day. A link to these edits can be found at and in the AAO’s 2019 Retina Coding: Complete Reference Guide.

There are two types of bundled codes. Mutually exclusive codes can never be unbundled and have an indicator of 0. Comprehensive codes, with an indicator of 1, may be paid separately under limited circumstances, and to do so they must meet the definition of modifier -59 per specific local coverage determinations (LCDs). Refer to Table 1 for examples of mutually exclusive and comprehensive bundled codes.

When procedures with multiple CPT codes are performed on the same patient on the same day, best practice is to review the NCCI edits related to those codes. Each CPT code combination should be reviewed for bundles. Some tests are bundled with other tests as well as with surgical procedures; some surgical procedures are bundled with other surgical procedures. These edits are updated quarterly (January 1, April 1, July 1, and October 1).

When Is Unbundling Appropriate?

Each bundling edit is identified with either a 1, indicating that unbundling is acceptable when certain criteria are met; a 0, indicating that the two codes involved are mutually exclusive and should never be unbundled unless an insurance payer policy allows under certain circumstances; or a 9, indicating that the bundling edit was made in error and has been reversed.

For bundled codes with an indicator of 1, it is appropriate to unbundle when the other bundled service is provided in the patient’s other eye. When unbundling is appropriate, modifier -59 would be appended to the appropriate CPT code.

To meet the criteria for unbundling, documentation must support either a different session, a different procedure or surgery, a different site or organ, a separate incision or excision, or a separate injury.


Laser to repair a retinal lesion using photocoagulation (67210) and laser to repair progressive retinopathy using photocoagulation (67228) are bundled with modifier 1 because the different laser procedures are treating the same contiguous structures of the same organ. If these procedures were performed in contralateral eyes, then unbundling these two codes would be appropriate. To unbundle the two codes, modifier -59 is appended to the CPT code 67228.

When bundled codes are incorrectly submitted to an insurance carrier, the CPT code with the lower allowable is typically paid and the code or codes with higher allowables are typically denied. Creating a process to verify NCCI edits prior to claims submission will ensure maximum reimbursement.


When two codes are bundled, the CPT code with the higher relative value unit (RVU) should be submitted. Maintaining a list of current RVUs per CPT code billed will allow you to best determine the appropriate coding. Note that each year the RVU value per CPT code may change.

For example, RVU for pars plana vitrectomy with endolaser panretinal photocoagulation (67040) and removal of preretinal cellular membrane (67041) are bundled under NCCI. The RVU value of these two codes changed in 2015 (Table 2).

Previously, 67040 was the higher valued code, but in 2015 67041 became the code with the higher value. When these two procedures are performed during the same surgical session, the CPT code 67041 should be billed. Incorrectly coding 67040 in this case could reduce reimbursement by approximately $109 per session.


The global period for surgical procedures can change periodically. For example, in January 2017, the global period for laser to repair a retinal detachment (67105) was adjusted from 90 days to 10 days for Medicare carriers.

When such changes occur, some commercial or Medicaid payers may also update the global period, while others may remain at 90 days. Promptly identifying the global period per CPT code and insurance carrier is essential to proper coding and reimbursement.

A change in the global period affects how and when office visits are billed. Incorrectly assigning a 90-day global period to a CPT code for which the insurance carrier recognizes a 10-day global period would result in a loss of revenue because visits from 10 days out to 90 days would be inappropriately coded as postoperative and not billed.

The assignment of the global period also defines whether a procedure is major (90-day global) or minor (0- or 10-day global). This is essential knowledge when one is considering the appropriate modifier for a same-day office visit for a procedure. The decision to perform major surgery the same day as an office visit would warrant appending the -57 modifier to the office visit code. For minor procedures performed on the same day as an office visit, the -25 modifier would be evaluated to determine if the documentation meets the definition of a significant, separately identifiable office visit. To illustrate this, Table 3 outlines the global periods associated with various laser procedures.


Medicare Administrative Contractors (MACs) publish LCDs, and CMS publishes national coverage determinations, or NCDs, to provide policies and guidelines for correct coding for specific procedures. These policies designate medical necessity, approved diagnosis codes, diagnostic testing requirements, and frequency edits as applicable. Commercial insurance carriers may also publish their own policies for procedures, and these are often posted on their websites or included in provider manuals. LCDs may vary by region, and they are revised periodically. To review and maintain a current copy of published LCDs for each MAC, visit

It is important not to apply one payer’s rule or perceived rule to all payers. Each insurance carrier may have unique policies that may differ from those of other carriers. Additionally, commercial payers may not recognize the same NCCI bundles published by CMS.


The protocols for coding retina procedures change at the margins from time to time, and these changes may have major downstream consequences if the new rules aren’t followed. By keeping up to date with developments in coding in the areas outlined in this article, you can maximize profitability for your practice and avoid costly audits.