Billing and Coding: Micro-Invasive Glaucoma Surgery (MIGS)

The information in this article contains billing, coding, or other guidelines
that complement the Local Coverage Determination (LCD) for Micro-Invasive
Glaucoma Surgery (MIGS) L37531.

CPT/HCPCS code(s) may be subject to National Correct Coding Initiative (NCCI)
edits. This information does not supersede NCCI edits. Please refer to NCCI
for correct coding guidelines and specific applicable code combinations prior
to billing Medicare.

**Coding Guidance:**

For noncomplex cataract removal with insertion of aqueous drainage system, use
CPT 66991.

For complex cataract removal with intraocular lens implant and concomitant
intraocular aqueous drainage device, use CPT code 66989.

iStent, iStent inject and Hydrus must be performed in conjunction with
cataract surgery on the same date of service and documented in the medical
record.

Since there is no specific CPT code for goniopuncture or so-called
microgoniotomy procedures, the unlisted CPT code 66999 (unlisted procedure,
anterior segment of the eye) should be reported in these instances.

Any procedures performed which consist of single or multiple small punctures
and/or injection of small amounts of viscoelastic, or other limited
interventions should be reported using unlisted CPT code 66999. Specifically,
goniotomy (CPT code 65820) should not be coded in addition to other angle
surgeries, stent insertions or Schlemm canal implants or if the incision into
the trabecular meshwork is minimal or simply incidental to another procedure.
In order to report a goniotomy, an extensive incision of the trabecular
meshwork around the eye, at the least and generally more than 3 clock hours,
must have been performed. Documentation regarding the reasonable and necessary
premise for the work must be present. Palmetto GBA may request additional
documentation on a case-by-case basis.

**Utilization:**

Medicare may cover only 1 unit per eye, per date of service of CPT code 66991
and 66989 for insertion of glaucoma drainage device(s) into the trabecular
meshwork, when performed in conjunction with cataract surgery and when the
medically reasonable and necessary criteria as stated in the LCD are met.

Although more than 1 drainage device into the trabecular meshwork of a single
eye on a single day of service, using an insertion tool loaded with more than
1 device, (e.g., iStent _inject_ ), may be performed, once the insertion tool
is deployed within the eye, there is negligible increase in work or expense.
Therefore, only 1 unit of 66991 and 66989 per eye, per day may be billed,
regardless of the number of devices inserted into a single eye on the date of
service.

Medicare may cover only **1 unit per eye, per date of service of CPT  code
0449T** for insertion of glaucoma drainage device(s) into the subconjunctival
space (e.g., XEN45), when the medically reasonable and necessary criteria as
stated in the LCD are met.

CPT code 0671T should not be billed with CPT code 66991 or 66989 for the
same beneficiary on the same date of service.

**Documentation Requirements:**

  1. All documentation must be maintained in the patient's medical record and must support the medical necessity of the services as directed in this article and be made available to the contractor upon request.
  2. Every page of the record must be legible and include appropriate patient identification information (e.g., complete name, dates of service[s]). The documentation must include the legible signature of the physician or non-physician practitioner responsible for and providing the care to the patient.
  3. The submitted medical record must support the use of the selected ICD-10-CM code(s). The submitted CPT/HCPCS code must describe the service performed.