In recent years, as the use of MIGS surgery in combination with cataract procedures has increased, the instances where the planned procedures can’t be completed have also risen. Correct billing depends on when and why the procedure was stopped. This can occur, for example, in cases where the cataract procedure can be completed without any difficulty but the placement of the aqueous drainage device can’t be done successfully and has to be removed from the eye. 

Here, we’ll discuss the coding implications for such occurrences.


Q: How should the incomplete procedure be billed?

The CPT manual includes a modifier appendix with this provision for procedures discontinued “… due to extenuating circumstances or those that threaten the well-being of the patient.” Novitas, a Medicare Administrative Contractor for several states, wrote in its fact sheet for surgical modifiers that, “discontinued due to elevated blood pressure” is a credible justification. This is described by modifier -53 for the surgeon’s claim, and either modifier -73 or -74 for the claim from the ambulatory surgery center. 

In this case, the operative report describes that the cataract portion of the operation was successful, but that the MIGS procedure wasn’t performed successfully. There are many potential reasons why the surgeon didn’t succeed in placing the ADD, including difficulty with visualization, equipment malfunction, a defective implant, surgeon inexperience, poor patient selection or intraoperative misadventure. 

While billing the planned procedure (66991) with modifier -53 is plausible, the use of modifier -53 should be reserved for a case that’s terminated for risk of sight-threatening reasons rather than failure to complete it.


Q: When is modifier -53 used?

Consider an inadvertent incision in an artery within the iris root resulting in a significant hemorrhage in the anterior chamber, obscuring the surgeon’s view of the anterior chamber angle, and additional viscoelastic can’t stop the bleeding. In this case, there’s an acute threat to the patient’s well-being that warrants discontinuation of the procedure. Such a situation necessitates a longer, more detailed operative report that explains what went wrong, why and how it was handled. This could support 66991-53.  


Q: How do you document support for discontinued procedures?

The Centers for Medicare & Medicaid Services (CMS) instruct that, “the operative report should specify the following:

• Reason for termination of the surgery;

• Services actually performed;

• Supplies actually provided;

• Services not performed that would have been performed if surgery had not been terminated; 

• Time actually spent in each stage, e.g., preoperative, operative, and postoperative;

• Time that would have been spent in each of these stages if the surgery had not been terminated; and

• HCPCS (or CPT) code for procedure had the surgery been performed.”


Q: How are surgeon’s claims processed with modifier -53? 

As a practical matter, the resolution of a claim for a discontinued procedure will rely on the payor’s assessment of the portion of the procedure completed. Was it half? A quarter? Operative notes may be requested by the payer to make this decision. In this example, none of the MIGS procedure was completed, so very little value would likely be ascribed to it.


Q: How are ASC claims for discontinued procedures handled by Medicare?

The Medicare Claims Processing Manual instructs payers how to handle claims based on when the case is terminated:

A. Contractors deny payment when an ASC submits a claim for a procedure that is terminated before the patient is taken into the treatment or operating room. 

B. Contractors pay 50 percent of the rate if a surgical procedure is terminated due to the onset of medical complications after the patient has been prepared for surgery and taken to the operating room but before anesthesia has been induced or the procedure initiated (use modifier -73).

C. Contractors make full payment of the surgical procedure if a medical complication arises which causes the procedure to be terminated after anesthesia has been induced or the procedure initiated (use modifier -74)…” 1 Later, it states:

G. ASC surgical services billed with the -73 modifier are not subject to the multiple procedure discount.1


Q: What is the billing alternative?

Frequently when one procedure is discontinued, another procedure is completed instead. If the reason the ADD implant isn’t implanted successfully doesn’t support modifier -53 (e.g., poor patient selection or inadequate surgeon skill), it’s reasonable to bill only for the cataract surgery (66984)—the completed procedure. 

If the surgeon bills for the completed procedure, modifier -53 isn’t required and the claim should be processed in the normal fashion.  


Q: What happens to the ASC payment?

If the ADD procedure can’t be supported but cataract surgery can, then reimbursement to the ASC is for 66984 only. There’s no reimbursement for the ADD device. It may be possible for the ASC to obtain a refund or a replacement product from the manufacturer for the unused device.

In conclusion, not all surgical procedures go as planned.  Accurate, detailed documentation in the operative note provides the necessary information for payment, whether a discontinued surgery is billed or the surgeon completes and bills for an alternate procedure. 


1. Medicare Claims Processing Manual (Chapter 14, §40.4C).

Mary Pat Johnson is a senior consultant at the Corcoran Consulting Group and is based in North Carolina. She can be reached at