CPR’s “Coding Corner” focuses on coding, compliance and documentation issues relating specifically to physician billing. This month’s tip comes from G. John Verhovshek, the managing editor for AAPC, a training and credentialing association for the business side of health care.   

CPT® modifier 79 Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period applies when the same provider (or a provider of the same specialty within a group of physicians billing under the same identification number) performs an unrelated surgical procedure during the postoperative period of another procedure. 

CPT® Appendix A (Modifiers) specifies, “The individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. The circumstance may be reported by using modifier 79. (For repeat procedures on the same day, see modifier 76).”

For example, explains CPT Assistant, “Modifier 79 is appended to report … a colposcopy performed during the global period of a mastectomy by the same surgeon. (Note that modifier 79 should not be reported with procedures that are related to the original procedure…”

Why bother?
Proper application of modifier 79 directly affects reimbursement. Modifier 79 tells the payor two things:

1. The procedure performed during the global period is unrelated, distinct, and separately payable. Payors should not “bundle” or otherwise include the procedure as part of the previous procedure’s global period, nor should they reduce payment for services properly reported using modifier 79


2. A new postoperative period should begin when the unrelated procedure is billed.

To further illustrate proper use, CPT Assistant (Sept. 2010) provides a second example:

A 68-year-old woman had an unfortunate landing while bicycling and sustained a mildly non-displaced closed fracture of the right distal ulna. Because of the patient's condition and the nature of the injury, closed manipulation treatment was performed in the operating emergency room, with placement of a long-arm plaster splint. The patient was discharged. Later in the day, the patient returned to the emergency department after experiencing nasal bleeding with clots. After unsuccessful pressure packing insertion and the use of local vasoconstrictors, the patient was returned to the operating room, where bleeding was controlled by repair of a posterior arterial hemorrhage with cautery.

The proper coding is 25535 Closed treatment of ulnar shaft fracture; with manipulation and 30905 Control nasal hemorrhage, posterior, with posterior nasal packs and/or cautery, any method; initial with modifier 79 appended. As CPT Assistant explains, “In this case, the medical documentation reflected that the postprocedural bleeding was not attributable to the initial operation.”

As seen in this example, the physician will perform a separate evaluation and management (E/M) service for the new problem before returning to the patient to the operating room. You may report this E/M service by appending modifier 24 (Unrelated E/M service by the same physician during a postoperative period) to the appropriate E/M service code.

Diagnoses must support separate nature of subsequent procedure
Application of modifier 79 is fairly straightforward; however, “the issues surrounding its use occur when providers and carriers disagree as to whether the procedure is actually ‘unrelated’ to the original procedure,” warns CPT Assistant (Sept. 2003). For example, the unrelated nature of the two procedures may be supported by distinct, separate diagnosis establishing medical necessity for each procedure.

Turn to 78 for related post-op procedures
If the subsequent procedure is related to the underlying condition that prompted the initial procedure, or performed to treat a complication of the initial procedure, modifier 78 likely is appropriate.

Like modifier 79, modifier 78 Return to the operating room for a related procedure during the postoperative period describes a return to the OR during the global period of another procedure, but modifier 78 indicates the subsequent procedure is related to the initial surgery (i.e., it is prompted by a complication or result of the initial surgery). When you append modifier 78 to a claim, the global period does not reset, and the payor may reduce payment to reimburse only for the “intra-operative” portion of the service.