Reimbursement for Goniotomy or Trabeculotomy AB Interno (MicroSurgical Technology)



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Q  What is trabeculotomy ab interno, also known as goniotomy?

A  Trabeculotomy ab interno is an ophthalmic surgical procedure to incise and partially remove trabecular meshwork to create an opening into Schlemm’s canal by way of the anterior chamber angle. The procedure is carried out by means of an ab interno approach from inside the anterior chamber under indirect visualization with a goniolens. So, the longstanding term for this procedure is goniotomy.


Q  What are the indications for goniotomy?

A  The primary indication for goniotomy is to clear the obstruction to aqueous outflow and associated abnormal internal drainage, which in turn lowers the intraocular pressure (IOP). Goniotomy is primarily performed to treat congenital glaucoma. Other indications include: aniridia, uveitic glaucoma associated with juvenile rheumatoid arthritis, juvenile open-angle glaucoma, and other abnormalities that create a blockage in trabecular meshwork in patients of all ages. Goniotomy is an alternative to bleb-forming glaucoma surgeries or tube shunts, and may be considered when antiglaucoma medications and/or laser trabeculoplasty have failed to adequately lower eye pressure.2


Q  What are the contraindications to goniotomy?

A  Goniotomy is contraindicated in patients where there is poor visualization of the angle, which may be due to corneal quality, lack of angle pigmentation or patient cooperation, active neovascularization, angle dysgenesis, and some forms of angle closure glaucoma.


Q  Can I use goniotomy as a primary or initial line of treatment for congenital glaucoma?

A  Yes. According to the guidelines from the American Academy of Ophthalmology, the primary treatment for congenital glaucoma is angle surgery, either goniotomy or trabeculotomy ab externo, and “[g]oniotomy is preferred when the cornea is clear enough to permit visualization of anterior segment structures”.1


Q  What CPT code describes goniotomy or trabeculotomy ab interno?

A  Use CPT code 65820 (Goniotomy). Additionally, CPT instructs: “For use of ophthalmic endoscope with 65820, use 66990”.3  Trabeculotomy ab externo (CPT 65850) is not equivalent to trabeculotomy ab interno – the surgical approach to Schlemm’s canal differs. Do not use CPT 65850 for an ab interno procedure.


Q  Does health insurance cover glaucoma surgery using goniotomy?

A  Yes, health insurance does cover glaucoma surgery for medically necessary procedures to treat glaucoma.


Q  Is goniotomy bundled with other services?

A  Yes. According to Medicare’s National Correct Coding Initiative (NCCI), 65820 is bundled with some other ophthalmic procedures, although not with cataract surgery codes 66982 and 66984. For example, goniotomy and ECP (66711) are bundled, as well cataract combined with ECP (66987, 66988). Check the NCCI edits for details.

Further, CPT instructs “Do not report 66174 in conjunction with 65820”. This instruction mirrors the mutually exclusive rules within NCCI.



Q  Is goniotomy compatible with ophthalmic endoscopy for reimbursement?

A  Yes. Ophthalmic endoscopy is defined in CPT as +66990. The “+” indicates an add-on code, which is not subject to the multiple procedure rule. Only a few ophthalmic procedures are eligible to be billed with +66990 – goniotomy is one of those. In the 2022 Medicare Physician Fee Schedule, it adds $88 to the surgeon’s reimbursement.


Q  What is the global surgery period for 65820?

A  CPT 65820 is considered a major surgical procedure; CMS defines it as having a 90-day postoperative period.


Q  What is the Medicare physician reimbursement for goniotomy?

A  The 2022 national Medicare Physician Fee Schedule (MPFS) allows $838 for goniotomy. This amount is adjusted by local indices so actual payment amounts vary. Other third party payers set their own rates.


Q  Does Medicare allow a facility fee for goniotomy performed in an ASC or HOPD?

A  Yes. Under current Medicare regulations, 65820 is eligible for a facility fee. The national 2022 ambulatory surgery center (ASC) allowed amount is $1,919; in the hospital outpatient department (HOPD), the allowable is $4,000. Allowed amounts are adjusted by local indices.
ASC: As with surgeons, when goniotomy and another major ophthalmic surgery are performed in the same operative session in an ASC, then the multiple procedure rules apply and reimbursement for the second procedure is reduced by 50%.

HOPD: When goniotomy and another major ophthalmic surgery are performed in the same operative session in a HOPD, then the multiple procedure rule does NOT apply. Goniotomy is assigned a J1 indicator and classified in APC 5492, a comprehensive APC. All covered Part B services on the claim are packaged with the primary J1 service for reimbursement, with few exceptions.


1. Clark RA. Primary Congenital Glaucoma. AAO EyeWiki Last update 10/29/21 Accessed 11/11/21
2. Wills Eye Hospital. Goniotomy Accessed 12/9/21
3. CPT 2022 Professional Edition


Provided Courtesy of MicroSurgical Technology – A Halma Company (888) 279-3323

Last updated January 1, 2022

The reimbursement information is provided by Corcoran Consulting Group based on publicly available information from CMS, the AMA, and other sources. The reader is strongly encouraged to review federal and state laws, regulations, code sets, and official instructions promulgated by Medicare and other payers. This document is not an official source nor is it a complete guide on reimbursement. Although we believe this information is accurate at the time of publication, the reader is reminded that this information, including references and hyperlinks, changes over time, and may be incorrect at any time following publication.

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