Ophthalmology and Optometry Coding Alert

Learn how to use modifiers -24 and -79 with the eye codes

Oh, those modifiers! They remain a mystery to many coders who think they know how and when to append them, yet frequently find their claims denied. Steer clear of common modifier pitfalls with our advice from the experts.

The modifier problem is so pervasive that improper use of modifiers has been cited as one of the top-10 billing errors by federal, state and private payers - not to mention that it is considered a major fraud, abuse and noncompliance issue.

Enter the Modifier Matrix: Understanding Claims Processing

We tend to think of the claims processing system in terms of how it should be done (what makes sense) versus how the computer systems work. For example, when you perform a surgery on the right eye and use the -RT modifier, then follow with a surgery on the left eye and append -LT, you assume that it was obvious that payment for one surgery did not include the other. But the computer processing your claim may not be programmed to distinguish between the right and left modifiers. The -RT, -LT, and   -E1 through -E4 modifiers are "informational" modifiers, not "payment" modifiers.

Consider a case in which you perform a service on one eye during the global period following the same procedure performed on the other eye. When coding the surgical procedure during the postoperative or global period for Medicare reimbursement, if you do not apply a modifier to indicate that the service is either -58 (Staged or related procedure or service by the same physician during the postoperative period), -78 (Return to the operating room for a related procedure during the postoperative period) or -79 (Unrelated procedure or service by the same physician during the postoperative period), the system will process your claim as though what you did was part of the global surgical package.

This can and will happen if the provider number you use is either for the same physician who performed the surgery or for a physician who is a part of the same group practice. The system isn't able to distinguish by physician, procedure code or diagnosis code that an obviously billable service should be paid. "With office visits, the same is true unless you mark the visit as 'unrelated' with modifier -24, 'significant and separately identifiable' with modifier -25, or the 'decision to perform major surgery' with modifier -57," says Raequell Duran, president, Practice Solutions, Santa Barbara, Calif. All ophthalmologists are categorized under the same specialty number, and the system is not able to recognize a glaucoma specialist from a retina specialist - or a visit for an unrelated condition.
 
Enter the modifiers. The little add-ons let the carriers know that there is something unusual with a bill, signaling that the carrier should look carefully at it rather than simply denying it. Nevertheless, carriers - local Medicare carriers as well as private insurance companies - often deal with the modifiers differently.

Below we spotlight modifier -24 (Unrelated evaluation and management service by the same physician during a postoperative period), considering a number of scenarios - the good, the bad, and the ugly - in which you should use it. Understanding -24 in its context and how best to justify its use can help you permanently unlock the mystery of one of these tricky modifiers.

The Good: Coding Unrelated Services

The easiest circumstance for using modifier -24 is when a patient comes back to the office during the global or postoperative period of a surgical procedure and requires an E/M (99211-99215) or ophthalmological (92002-92014) service for a condition completely unrelated to the original surgery.

For example, a patient still in the 90-day global period following cataract surgery to her left eye (366.xx, Cataract), visits the office for a glaucoma follow-up. You should code the visit using a 365.xx code for the glaucoma diagnosis and appending -24 to the appropriate office visit CPT code. Your carrier should provide full reimbursement for the service rendered.

The difference in the diagnosis codes for the surgery (for cataract) and the follow-up visit (for glaucoma) sometimes provides carriers with a clear indicator of the unrelated nature of the E/M service and the condition that required the surgery. Different carriers have their own ways of handling this; however, as a general rule, you should make indications for this unrelated service clear in the chart documentation and appeal any denials.

Easy enough - but if the diagnosis code for the visit during the global period is the same as or similar to the one that required surgery, you are going to need additional modifiers to make your case.
 
The Bad: E/M Services With Shared Diagnoses

When patients come in during the global period following surgery for E/M services for the same diagnosis but in the other eye, the eye modifiers can be a lifesaver when used with modifier -24. One good practice for keeping details about surgical procedures distinct is to append the appropriate eye modifier in all cases. That way, if the same condition occurs in the other eye and requires that the patient come in for E/M service, you will already have on record a clear differentiating factor for the two services.

For example, a patient has a laser procedure on the left eye (67228, Destruction of extensive or progressive retinopathy [e.g., diabetic retinopathy], one or more sessions; photocoagulation [laser or xenon arc]). You should code the service 67228-LT. If the patient came back in within the global period requiring E/M services for the same diagnosis, your original use of the eye codes on the first procedure makes using modifier -24 that much more effective with your carriers. You could code this second visit 92012-24-RT.

Modifier -24 is a payment modifier, while "the -RT,    -LT, and -E1 through -E4 modifiers are considered 'informational' modifiers," Duran says, and you should code them in that order. The first modifier, the payment modifier, tells the carrier that the service is unrelated to the previous surgery and should be paid. The eye modifiers provide specific data to support your claims. They distinguish the eye receiving the initial treatment from the eye receiving treatment in the global period. Coding both events with the eye codes helps you prove your case when filing claims (or fighting denials).

So, what happens when the E/M service with modifier -24 results in a decision for surgery and a new procedure during the global period?

The Ugly: E/M, Surgery and Unrelated Procedure

To take the example above a step farther: The patient who had 67228 performed in the left eye (67228-LT) comes in for E/M service for symptoms that suggest a vitreous hemorrhage (379.23) in the right eye. The E/M service, as we have seen, gets modifier -24 (Unrelated evaluation and management service by the same physician during a postoperative period) as well as the eye code, to signal that this is different from the original surgery (92012-24-RT).

You should append modifier -57 (Decision for surgery) to the E/M code to show that the visit is not included in the preoperative period for the right eye because during the visit the ophthalmologist initially decided the surgery was necessary. For example: 9921x-24-57 or 9200x-24-57

When coding the procedure itself, you should append modifier -79 to indicate that the service is unrelated to the one that initiated the postoperative period. Follow -79 with the appropriate eye modifier.

Note: Append modifier -79 before the eye modifier because modifier -79 is the payment modifier. Payment modifiers explain why your claim should be paid outside the global surgical package.

The Exception (of Course): Cataract Surgery

When coding for cataract surgery (66830-66986) in the postoperative period using the -LT and -RT modifiers, remember that the guidelines are somewhat different. Most carriers maintain that you cannot bill a visit within the cataract surgery postoperative period for the decision to perform a similar procedure on the other eye. The general claim is that you had already decided that the second eye should be treated when you decided to perform surgery on the first eye.

Many carriers consider cataract removal an elective procedure that can be performed at any time. That makes the condition different from an exacerbation of an underlying disease process that requires a nonelective procedure. Consequently, modifier -24 may not suffice when you seek reimbursement for an E/M visit performed within the cataract surgery's global period.

While you may not be reimbursed for your E/M service, your carrier will pay for the cataract surgery, and you should use the eye modifier to do so. You should report the procedure with modifier -79 and the appropriate eye modifier if done within the global period of the first cataract surgery. If you billed for the first procedure with the appropriate eye modifier, you should receive the full Medicare fee schedule amount for the second procedure.

For instance, during the cataract surgery postoperative period for the left eye, the ophthalmologist notices that the right eye - which had cataract surgery with an intraocular lens (IOL) a year ago - has developed a significantly cloudy posterior capsule that requires surgery. When the procedure (66821, Discission of secondary membranous cataract [opacified posterior lens capsule and/or anterior hyaloid]; laser surgery [e.g., YAG laser] [one or more stages]) is performed that day or the next day, you should report the office visit (99211-99215 or 92012-92014) with modifiers -24 and -57. Append modifier -79 and modifier -RT to the surgical procedure code. Link the diagnosis code 366.53 (Cataract; after cataract; after-cataract, obscuring vision) to 66821-79-RT to show medical necessity for the procedure.

'The Easy'

Don't use -24 when it's not necessary. For instance, your ophthalmologist performs epilation to correct trichiasis (67820). The procedure has a 0- to 10-day global period. The patient comes back two weeks later for a glaucoma follow-up. You should not append modifier -24 to the glaucoma follow-up visit because the physician performed the second service after the global period for the epilation had expired.

Justify Modifier -24 Every Time

"As far as modifier -24 is concerned, documentation is the key," says Christine Fitzgerald, CPC, accounts manager for The Rhode Island Eye Institute. Many compliance consultants recommend using separate pieces of paper to document the office visit and the minor procedure, although this is not a Medicare requirement. You can even create a "minor procedure" form by making a dated entry for each procedure performed and documenting the procedure after a treatment plan has been devised for that particular office visit.

And remember to keep notes clear and in long-hand whenever possible - words work best for auditors. If the physician's notes are abstracted, the abstractor may not pick up on all of the details. This is particularly important when billing for both office visits and procedures.