Modifier 24 is to be used to report an unrelated E&M service during the global period of a previous procedure, including services by other "same-specialty physicians". This means that a surgeon covering postoperative patients for his or her partner does not bill for services provided. Physicians in the same group practice and in the same specialty must bill and be paid as though they were a single physician.

For CMS, all medical and surgical post-surgery complications are included in the global payment and cannot be billed separately unless a return to the operating room is required. Treatment of wound infections and other complications cannot be reported. CPT defines the surgical package as "typical" postoperative care. Medicare has classified major and minor surgeries and has determined what services are inclusive and not inclusive with the global package.

Medicare has also determined the preoperative and postoperative days allowed for each type of surgery. The preoperative period included in the global fee for major surgery is one day, with 90 days for the postoperative period. The preoperative period for minor surgery is the day of the procedure, with the postoperative period of 0 or 10 days, depending on the procedure. For endoscopic procedures, except for those requiring an incision, there is no postoperative period. All global period days can be accessed on the CMS website for review.

Correct use of modifiers makes claims processing easy and providers receive the due reimbursement without any hassle. On the other hand, incorrect use of modifiers will result in payment denials and other complications.