In coding, we assume “CPT” is understood. This is an abbreviation for Current Procedural Terminology, and it is a valuable reference manual for reporting services on claims for reimbursement. The words and phrases it contains are carefully chosen for clarity, much like a dictionary. Proper usage ensures accuracy, while improper use is confusing or misleading. The AMA’s CPT Manual is constantly growing and changing as procedures are added, revised, and deleted. Still, there are gaps that arise when new instruments, implants, and techniques are introduced.

The manual states, “Do not select a CPT code that merely approximates the service provided. If no such specific code exists, then report the service using the appropriate unlisted procedure or service code.” How are we to apply this instruction? Let’s consider some examples.

Laser Capsulotomy

Following cataract surgery, the remaining capsule may opacify on the posterior capsule or on the anterior capsule. In CPT, we find the following: “66821: Discission of secondary membranous cataract (opacified posterior lens capsule and/or anterior hyaloid); laser surgery (e.g., YAG laser) (1 or more stages).” Alternately, use 66999, “Unlisted procedure, anterior segment of eye,” to report a laser capsulotomy of the anterior capsule.

Injection

Viscoelastic may be injected into the anterior chamber (AC) for early postoperative hypotony, or into Schlemm’s canal, behind the trabecular meshwork during MIGS. In CPT, we find the following: “66020: Injection, anterior chamber of eye (separate procedure); air or liquid.” When the injection of viscoelastic is not part of another MIGS procedure, such as canaloplasty, use 66999, “Unlisted procedure, anterior segment of eye” to report an injection of viscoelastic into Schlemm’s canal rather than the AC.

Corneal Relaxing Incisions

Astigmatism may be surgically induced or pre-existing in a previously unoperated eye. In CPT, we find the following: “65772: Corneal relaxing incision for correction of surgically induced astigmatism.” Alternately, use 66999, “Unlisted procedure, anterior segment of eye” to report a corneal relaxing incision in a previously unoperated eye.

Wound Revision

Following glaucoma surgery, a complication may arise that requires a reoperation, such as a failed bleb. In CPT, we find the following: “66250: Revision or repair of operative wound of anterior segment, any type, early or late, major or minor procedure.” Use 66999, “Unlisted procedure, anterior segment of eye,” to report a revision or repair that is outside of the anterior segment. The anterior segment is defined as the structures located between the front surface of the cornea and the vitreous.

Insertion of Xen Gel Stent

There are 2 ways to implant a Xen Gel Stent (Allergan/Abbvie): from inside the eye and from outside the eye. There are 2 different CPT codes depending on the surgical approach. 0449T is “Insertion of aqueous drainage device, without extraocular reservoir, internal approach into the subconjunctival space; initial device” and 66183 is “Insertion of anterior segment aqueous drainage device, without extraocular reservoir, external approach.” Because there is a specific CPT code for each surgical approach, an unlisted procedure code is not required.

Consequences of Unlisted CPT Codes

Within the Medicare Physician Fee Schedule, there are no RVUs assigned to 66999 or any other unlisted procedure code. Payment is determined on a case-by-case basis, and the payer requires additional chart documentation to make the determination. The amount depends on the duration of the procedure, the work involved, the complexity of the maneuvers, and the associated risks.

Adjudication takes time, so claims are not paid as quickly as other well-defined procedures. Postoperative periods are not assigned to unlisted procedure codes; the surgeon will typically charge for each visit after surgery.

Within the Medicare Outpatient Prospective Payment System, an ambulatory surgery center is ineligible for reimbursement of unlisted procedures, while a hospital outpatient department may be reimbursed. As a practical matter, an unlisted procedure code is your last choice after all other code selections are found to be inadequate. They exist to fill a gap in the available codes, because close is not good enough in CPT. GP

Kevin J. Corcoran, COE, CPC, CPMA, FNAO, is president of Corcoran Consulting Group in San Bernardino, California.