90-day global (major surgery)

When CMS assigns a global surgery indicator of 090 to a CPT code, it signals that the procedure is a major surgery and that a single bundled payment covers a defined package of services: one pre-operative visit on the day before surgery, all intraoperative work, and all routine follow-up visits related to recovery through the 90th post-operative day. Common orthopedic examples include open fracture fixation, total joint arthroplasty, and spinal fusion procedures. The operating surgeon—or their group practice billing under a shared tax ID—is expected to submit only the surgical CPT code; separately billing routine post-operative visits during this window results in a duplicate-payment error.

The global package also covers management of complications that do not require a return to the operating room, such as wound care or early infection treated in the office. Services that fall outside the bundle include the initial evaluation when the decision for surgery is made (billable separately with modifier 57), care by a different provider who has not formally accepted a transfer of care, services unrelated to the surgery, and any complication requiring a return trip to the OR. When care is formally split—for example, a hospitalist manages post-discharge recovery while the surgeon handles the operative component—modifiers 54, 55, and 56 allow each provider to bill for their respective portion of the global package, with payment divided according to CMS's pre-set percentage allocations (roughly 10% pre-op, 69% intra-op, 21% post-op).

CMS has tracked post-operative visit patterns under a MACRA-mandated data collection program and found that orthopedic surgeons report post-operative visits at an observed-to-expected ratio well below 1.0, which flags practices for potential audit scrutiny in both directions—overbilling and underbilling. Accurate use of CPT 99024 for routine post-op visits and appropriate modifiers for separately billable services is therefore both a compliance and a reimbursement necessity.

Mishandling the 90-day global period is one of the most common sources of both claim denials and OIG audit findings in orthopedic practices. Billing a standard E/M visit during the post-operative window without a modifier causes the payer to bundle—and deny—the claim. Conversely, failing to bill separately for a genuinely unrelated condition or an unplanned return to the OR leaves revenue on the table and may also misrepresent the clinical picture. CMS data showing a low observed-to-expected ratio for post-op visits in orthopedics means that practices deviating significantly from peer norms—in either direction—attract audit attention, making precise modifier selection and documentation a financial and compliance imperative.