Medicare Reimbursement for iStent Trabecular Micro-Bypass



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Q  What is the iStent® trabecular micro-bypass system?

A  iStent® is a small (1 mm X 0.33 mm) device designed to fit into Schlemm’s canal to facilitate aqueous drainage from the anterior chamber.  It is made of non-magnetic, surgical grade titanium; it is coated with heparin and comes preloaded in an inserter.  There are two different orientations of iStent – one for each eye.1.


Q  What are the indications for iStent?

A  As approved by the FDA on June 25, 2012, the iStent “…is the first device approved for use in combination with cataract surgery to reduce pressure inside the eye (intraocular pressure) in adult patients with mild or moderate open-angle glaucoma and a cataract who are currently being treated with medication to reduce intraocular pressure.”  The FDA also noted in the Press Release that “This option may be considered earlier in the disease process than some other types of surgical glaucoma treatments.2.


Q  Is iStent indicated for patients with glaucoma in the absence of cataract?

A  No.  The FDA approval specifies “in combination with cataract surgery”.  All other uses are “off-label” and experimental or investigational.  As a general rule, third party payers do not cover experimental and investigational procedures.


Q  What CPT code should be used for implantation of iStent?

A  A category III CPT code, 0191T, established on July 1, 2008, applies.  It reads: “insertion of anterior segment aqueous drainage device, without extraocular reservoir; internal approach, into the trabecular meshwork.”  Also, the appropriate cataract removal procedure code would appear on the claim.


Q  Does Medicare cover this procedure?

A  Yes, in most cases, the Medical Directors for each Medicare Administrative Contractor (MAC) have expressed a willingness to cover 0191T and are paying claims.  However, many of the MAC websites do not contain a published policy to that effect.


Q  If Medicare does not cover this procedure, who is responsible?

A  The beneficiary is financially responsible if you obtained an ABN prior to surgery.  Explain to the patient why the procedure is necessary, and that Medicare will likely deny the claim.  Ask the patient to assume financial responsibility for the charge; get the patient’s signature on an Advance Beneficiary Notice of Noncoverage (ABN) prior to surgery.  You may collect your fee from the patient at the time of service or wait for a Medicare denial.  If both the patient and Medicare pay, promptly refund the patient or show why Medicare paid in error.


Q  What does the Medicare fee schedule say for 0191T?

A  Payment rates vary by type of provider and site of service.  Published rates do not guarantee coverage or payment.  In 2013, the Medicare allowed amounts are:

  • Physician ………………… MAC discretion
  • ASC Facility Fee …………….. $1,671.00
  • HOPD Facility Fee …………… $2,977.93

These amounts are adjusted in each locality by local wage indices and are additionally subject to payer restrictions which can vary considerably.


Q  What is the global period for CPT 0191T?

A  There is no specified global period for 0191T.  The global period for concurrent cataract surgery is 90 days.  As a practical matter, the known interval outweighs the unknown interval.


Q  Is there separate Medicare reimbursement for the iStent device?

A  No.  Medicare payment for the iStent glaucoma drainage device is included in the facility reimbursement for 0191T.  On UB-04 claims, use revenue code 278 to report the iStent.


Q  What about implanting two iStents in the same eye during the same operation?

A  Implanting two iStents has not been studied in a clinical trial.  The directions for use are for a single iStent in an eye.


Q  How should we bill if one surgeon removes the cataract and another implants the iStent?

A  If these procedures are done at the same session, and both surgeons are part of the same group, the combined procedure is subject to the multiple procedure rules.  The larger procedure is reimbursed based on 100% of the allowed amount and the smaller procedure is reduced 50%.

When the surgeons are not part of the same group, each bills and receives reimbursement for the procedure each performed.


Q  Are there any NCCI edits or bundles for CPT 0191T?

A  Yes. As of January 1, 2013, NCCI edits include 66170, 66172, 66180 and 0192T.  Some other, more esoteric, edits apply as well.  In addition, all edits in place for the concurrent cataract procedure pertain.

Check NCCI edits periodically; they change quarterly.  Most third party payers follow NCCI edits, but not all.  Check your payer contracts.


Q  May gonioscopy be billed at the time of iStent implantation?

A  Gonioscopy (CPT 92020) is required to implant the iStent.  Because gonioscopy carries the “separate procedure” designation in CPT, it should not be billed when it is integral to the performance of another procedure (CPT 0191T in this case).


1.  Glaukos (Manufacturer) website.  Link here.

2.  FDA News Release June 25, 2012.  Link here.


Last updated March 1, 2013


The reader is strongly encouraged to review federal and state laws, regulations and official instructions promulgated by Medicare and other payers.  This document is not an official source nor is it a complete guide on all matters pertaining to reimbursement.  The reader is also reminded that this information, including references and hyperlinks, can and does change over time, and may be incorrect at any time following publication.


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