Optimizing Orthopaedic Care: A Guide to Global-Period and Transfer-of-Care Modifiers

Editor’s note: AAOS partners with KarenZupko & Associates (KZA) on the organization’s coding education, and KZA often provides content for AAOS Now. For more information, visit aaos.org/membership/coding-and-reimbursement.

The preoperative, intraoperative, and postoperative sections of surgical care define the “global period.” The global period refers to a specified timeframe (0, 10, or 90 days) during which all services related to a surgical procedure are included. For musculoskeletal procedures, reported using Current Procedural Terminology (CPT) codes 20100 to 29999, the relative value units (RVUs) are dispersed among the pre-, intra-, and postoperative periods by 10 percent, 69 percent, and 21 percent, respectively. Neurosurgery procedures (CPT 61000 to 64999) have slightly different RVU distribution (11 percent, 76 percent, and 13 percent, respectively). Maintaining continuity of care for the patient during the global period is critical to overall outcomes, and accurate documentation and coding are essential to proper reimbursement and effective coordination of patient care.

In 2025, the Centers for Medicare & Medicaid Services (CMS) expanded its documentation requirements when a provider performs a surgical procedure with a 90-day global surgical package but transfers postoperative care to another provider outside of their group practice. This change was made to enhance continuity of patient care through better communication between providers, standardize documentation with clear protocols for transfer-of-care coordination, reduce errors in postsurgical care, increase transparency regarding reimbursement in line with value-based models of care, and reduce overpayments or duplicate billing. Medicare expanded its guidance to say that postoperative care can be transferred to a provider of the same specialty but not within the same group practice’s taxpayer identification number.

Previous CMS guidance required a written transfer of care from the operating surgeon and a documented acceptance of care by the provider furnishing postoperative care only. However, this process often was not occurring, leaving providers unaware of previous treatments for their patients.

Transfer-of-care modifiers
Both Medicare and commercial payers reimburse modifiers 54, 55, and 56 when they are appended to surgical procedure codes with a 90-day global period to classify the different components of the global period. The provider adds the modifier to the CPT code representing the procedure being performed. However, codes are not to be appended to evaluation and management (E/M) codes. The use cases for these modifiers are as follows:

• Modifier 54—Surgical Care Only: Append modifier 54 when a physician performs only the surgical portion and does not intend to perform the postoperative care, or when a formal, informal, non-documented, but anticipated transfer of care is expected.
• Modifier 55—Postoperative Management Only: Append the surgical CPT code when a physician provides only postoperative care after surgery. Modifier 55 requires a formal, documented transfer of care from both the transferring and receiving providers. Documentation should include record of the date of transfer and details of the scope of services provided.
• Modifier 56—Preoperative Management Only: Append the surgical CPT code when a physician provides only preoperative care before surgery and there is a formal written transfer of care. This modifier is rarely used.

When the provider rendering postoperative management does not have a formal documented transfer of care, bill an appropriate E/M code (9920x to 9921x).

HCPCS code G0559
Medicare created Healthcare Common Procedure Coding System (HCPCS) code G0559 to be submitted alongside E/M services for a provider furnishing postoperative care. With a total RVU of 0.27, it can only be billed once within the 90-day global period to capture the work associated with follow-up care when the provider was not involved in the preoperative or surgical process. It can be appended with or without knowledge of whether the surgeon used modifier 54. It is unclear whether private payers will reimburse G0559.

The details for code G0559 are as follows: “Postoperative follow-up visit complexity inherent to evaluation and management services addressing surgical procedure(s), provided by a physician or qualified health care professional who is not the practitioner who performed the procedure (or in the same group practice) and is of the same or of a different specialty than the practitioner who performed the procedure, within the 90-day global period of the procedure(s), once per 90-day global period, when there has not been a formal transfer of care and requires the following required elements, when possible and applicable:

• Read available surgical notes to understand the relative success of the procedure, the anatomy that was affected, and potential complications that could have arisen due to the unique circumstances of the patient’s operation.
• Research the procedure to determine expected postoperative course and potential complications (in the case of doing a post-op for a procedure outside the specialty).
• Evaluate and physically examine the patient to determine whether the postoperative course is progressing appropriately.
• Communicate with the practitioner who performed the procedure if any questions or concerns arise. (List separately in addition to office/outpatient evaluation and management visit, new or established.)”

Case example
A patient sustains a left bimalleolar fracture on Jan. 12, 2025, while on vacation and is treated with a closed treatment of a bimalleolar ankle fracture with manipulation. He returns home and sees his local orthopaedic surgeon on Jan. 20, 2025. Physician A, who performed and reported preoperative and surgical care on Jan. 12, must report the following CPT code and modifier: 27810-54,LT and 9920x-57. Physician A will receive 10 percent of the total RVU for the preoperative work and 69 percent of the total RVU for the intraoperative work for CPT code 27810.

There are two options for how physician B, who performs and reports postoperative care during the follow-up on Jan. 20, can proceed:

• Option 1: If a formal written transfer of care is received and accepted, physician B would report the following CPT codes and modifiers: 27810-55,LT and 99024. For follow-up visits for the remainder of the 90-day period, physician B would bill 99024. Physician B would receive 21 percent of the total RVU for CPT code 27810.
• Option 2: If no formal written transfer of care was obtained or accepted, physician B would report the following CPT codes and modifiers: 9920x or 9921x and G0559. Physician B would then bill all follow-up visits with the appropriate level of E/M code (9921x).

Billing for nonoperative fracture care, CPT code 27808, would not be appropriate in either option.

For surgeons providing only preoperative and intraoperative care, modifier 54 must be appended to the surgical CPT code. In the case of a patient who was treated elsewhere for a procedure, unless there is a documented transfer of care, a surgeon providing postoperative care should bill the appropriate level E/M code for each visit and G0559 once during the 90-day postoperative period.

Understanding and correctly applying transfer-of-care modifiers are essential for ensuring accurate reimbursement and continuity of patient care. With CMS’ expanded documentation requirements in 2025, providers must take extra steps to ensure transparency in the transfer of postoperative management. By appropriately using modifiers 54, 55, and 56—and, when necessary, HCPCS code G0559—practices can avoid compliance risks while maintaining the integrity of surgical billing. Effective communication, proper documentation, and adherence to these guidelines will help streamline patient transitions and support optimal care outcomes.

Christine Banks, RHIA, CPC, CPCO, is a senior consultant with KZA.

Reference

1. Centers for Medicare & Medicaid Services: MLN907166 – Global Surgery. Available at: https://www.cms.gov/files/document/mln907166-global-surgery-booklet.pdf. Accessed March 7, 2025.