As organized optometry continues to fight for scope of practice expansion, clinicians must arm themselves with the knowledge necessary to incorporate the new care regimens into their practices. More advanced surgical procedures such as laser trabeculoplasty, for example, call for not just new tools, but also the know-how to code for them properly. 

The Stats

Laser trabeculoplasty, CPT code 65855, is defined by the CPT as “trabeculoplasty by laser surgery, 1 or more sessions (defined treatment series).” Argon laser trabeculoplasty, selective laser trabeculoplasty and diode laser trabeculoplasty are options used in the treatment of primary open-angle glaucoma (POAG)—the medical necessity you will need to prove. 

These may be performed as the initial treatment, when medical therapy fails, or when a patient is unable to tolerate medications. They are considered medically necessary for these following indications:

  • Primary treatment for open-angle glaucoma.
  • POAG when the raised intraocular pressure is unresponsive to topical or oral medications.
  • POAG with normal pressure and evidence of optic nerve damage. 
  •   The CPT characteristics that further define this code include:
  • CMS National Average Maximum Allowable Reimbursement: $252.00
  • Bilateral 150% procedure: this CPT designation means that if the code is billed with the bilateral modifier or is reported twice on the same day by any other means (e.g., with -RT and -LT modifiers, or with a “2” in the units field), consider the payment for these codes when reported as bilateral procedures on either (a) the total actual charge for both sides or (b) 150% of the fee schedule amount for a single code—whichever is lower. If the code is reported as a bilateral procedure and is reported with other procedure codes on the same day, apply the bilateral adjustment before applying any multiple procedure rules.
  • Has a global period of 10 days following the date of surgery.
  • Follows the rules for a minor surgical procedure.

Dabbling in the Minors

The rules that govern laser trabeculoplasty as a minor surgical procedure are where the compliance issues come into play. Many forget that minor surgical procedures have their own set of compliance rules, ignorance of which can lead to claim rejection, non-payment for services, inappropriate use of modifiers and, ultimately, an adverse audit result. 

A minor surgical procedure has a global period of 0 or 10 days, while major surgical procedures have global periods of 90 days. While some states allow optometrists to perform major surgical procedures, the vast majority of ODs perform minor surgical procedures on a daily basis. Perhaps the two most common mistakes ODs make when billing for these minor surgical procedure is billing for an office visit on the same day as the minor surgical procedure and inappropriately using modifier -25. The National Correct Coding Initiative Policy Manual for Medicare Services clearly sets the record straight:

“If a procedure has a global period of 000 or 010 days, it is defined as a minor surgical procedure. In general E&M services on the same date of service as the minor surgical procedure are included in the payment for the procedure. The decision to perform a minor surgical procedure is included in the payment for the minor surgical procedure and shall not be reported separately as an E&M service. However, a significant and separately identifiable E&M service unrelated to the decision to perform the minor surgical procedure is separately reportable with modifier 25. The E&M service and minor surgical procedure do not require different diagnoses.”1

Following these rules is paramount when performing any minor surgical procedures, yet many get caught up in the excitement of scope of practice expansion and access to new procedures and forget the basics. The key to successfully integrating such new techniques and care paradigms into your practice is maintaining the highest level of awareness with both patient care and medical record keeping and coding.

Send your own coding questions and comments to

1. Centers for Medicare and Medicaid Services. National Correct Coding Initiative Edits. Accessed June 1, 2018.