Procedure Coding: When to Use the 79 Modifier
This is part of the Modifier Series, the articles include:
- Modifers 59, 25, and 91
- Modifier 59
- Modifier 25
- Modifier 26
- Modifier 22
- Modifier 51
- Modifier 53
- Modifier 58
- Modifier 52
Chances are, if you commonly bill for procedural services which are accompanied by a global period, you’ve had at least some experience with modifier 79. This is because the 79 modifier is appended to surgical procedures done within the global period of a separate, prior procedure. Only, the two procedures cannot be at all related. As you might expect, this can cause confusion even amongst experienced billing and coding staff. Modifier 79 may require precise application, but we’re here to help. This article will serve to clarify when and how to use modifier 79, so you can be confident in your coding knowledge and ensure that you’re getting paid appropriately for all your performed procedures.
Defining Modifier 79
Modifier 79 is defined by CPT as an “unrelated procedure or service by the same physician during the postoperative period.” Essentially, it’s the modifier you’ll need to use when a provider has performed two unrelated procedures within the same day, and/or when the second procedure is performed within the global period of the first procedure. The 79 modifier would be appended to the second of the two procedures. Typically, the second procedure would also be linked to a different diagnosis, further demonstrating to the payer that it is distinctly separate from the first. Let’s look at examples of modifier 79 in action to get a better idea of how to use it appropriately.
Modifier 79 Example 1
A patient who is in the global period of care for a fracture to their right leg falls and injures their left wrist. Arthroscopic wrist surgery is unrelated to the global period created by treating the right leg, so any procedure for the left wrist would have a 79 modifier appended. Services that qualify for a 79 modifier may be performed anywhere, as long as they are performed by the same physician.
Modifier 79 Example 2
A surgeon amputates a patient’s right little finger because of an infection. Within the postoperative period of this surgery, the same physician amputates the patient’s left little toe after it is crushed in an accident. Modifier 79 would be used on the second surgery because the two operations are completely unrelated, even though they may seem similar.
Modifier 79 Example 3
A patient presents to his dermatologist with actinic keratoses, which the physician removes via cryosurgery (CPT code 17000, 17003, or 17004, depending on how many are treated.) The same patient comes back 7 days later, saying he also meant to consult the physician about the suspicious lesion on his chest. The physician thinks the chest lesion is a skin cancer and biopsies it. The biopsy would need a modifier 79 since that procedure fell within the 10-day global period for the cryosurgery.
The 79 modifier may have its points of confusion, but a little clarification can go a long way. Here are the important specifics to keep in mind about modifier 79:
- It can only be submitted with surgical codes.
- Append 79 to the second procedure done within the global period.
- It only applies when the second procedure is done by the same physician within the global period of the prior procedure.
As with all other types of modifiers, supporting documentation should be maintained in the patient’s medical record. The documentation needs to substantiate that the surgeries are unrelated to rule out any questioning by the payer.