Modifier 79 is often overlooked as a potential area for misuse; however, investigators should keep it on their radar.  This modifier is defined in the AMA CPT manual as:

Unrelated Procedure or Service by the Same Physician or Other Qualified Health Care Professional during the Postoperative Period. 

The individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. This circumstance may be reported by using modifier 79. (For repeat procedures on the same day, see modifier 76.) [1]

In 2013, the verbiage was changed slightly to add "or Other Qualified Health Care Professional..." and is thought to be due to the increased usage of physician assistants, nurse practitioners, and other non-physician practitioners in many healthcare settings. [2]

Appropriate use for this modifier is indicated for circumstances when a patient undergoes a procedure that has a global postoperative period, and needs to return to the same practice for another procedure during that global period. 

An example of appropriate use for this modifier would be if a patient is treated for a fractured ankle.  He/she is discharged and sent home.  Two weeks later, the patient falls while attempting to go up the steps and breaks a bone in his/her hand.  The patient returns for treatment to the same physician.  The treatment of the hand fracture would be billed with modifier 79.

Unfortunately, this modifier is prone to abuse.  According to a report by the Office of Inspector General (OIG), they launched an investigation after receiving allegations that a provider was billing for podiatry surgeries that were never performed.  The investigation substantiated the allegations and revealed that the provider billed for surgeries for his patients every five to six days. To avoid detection, nearly every time the provider billed for surgery, Modifier 79 was used. [3]

Investigators should be on the lookout for excessive use of Modifier 79 among their providers, as well as spikes in billing among peer groups.  If a provider stands out from his/her peers for usage, it is possible they may be attempting to unbundle the global surgical period. 

Using a data mining tool such as PostShield™, can help identify these aberrant billing patterns and more. 

If you have any questions, you may email our Subject Matter Experts at [email protected].