Summary & Overview
CPT 20955: Vascularized Fibula Bone Graft for Major Defect Reconstruction
CPT code 20955 denotes a microvascular free fibula bone graft: harvesting fibular bone with its arterial and venous supply and transplanting it to reconstruct major bone defects with restored vascularity. This procedure is clinically significant for complex orthopedic and maxillofacial reconstructions where reestablished blood flow improves healing, reduces nonunion risk, and supports bone regeneration. Nationally, the code captures high-complexity reconstructive services performed in hospital operating rooms or ambulatory surgical centers by surgical teams with microsurgical expertise.
Key payers in the national analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of how this service is described clinically, typical sites of service, and the context for utilization of vascularized bone grafting in major defect repair. The publication also outlines common billing modifiers associated with surgical procedures and highlights where data was unavailable in the input.
This report is intended to inform health policy analysts, clinical coders, and revenue cycle professionals about the clinical definition and billing context of CPT code 20955, provide benchmark and policy-oriented perspectives where available, and summarize the clinical scenarios that typically generate use of this code.
Billing Code Overview
CPT code 20955 describes a surgical procedure in which a provider harvests bone graft material from the fibula together with its active vascular supply (arteries and veins) and transplants it to fill a major bone defect at a recipient site, restoring blood flow to promote faster healing and growth. This is a microvascular free fibula bone graft with reestablished vascular supply.
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Service type: Microvascular free vascularized fibular bone grafting for major bone defect reconstruction
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Typical site of service: Operating room or hospital inpatient/ambulatory surgical facility, where complex reconstructive surgery and microsurgical vascular anastomosis are performed
Clinical & Coding Specifications
Clinical Context
A 45-year-old male presents with a large segmental tibial bone defect after a high-energy open fracture sustained in a motorcycle collision. Prior attempts at internal fixation and nonvascularized grafting failed to achieve union, and there is concern for nonunion with soft-tissue compromise. The orthopedic microsurgery team plans a free vascularized fibular bone graft to reconstruct the tibial defect: the surgeon harvests the fibula with its peroneal artery and concomitant veins, transports it to the leg, and performs microvascular anastomoses to recipient vessels to restore blood flow and promote bone healing.
The clinical workflow includes preoperative imaging (CT and angiography as needed) and medical optimization, operative staging with general anesthesia in an operating room equipped for microsurgery, harvest of the vascularized fibular graft, microsurgical transfer and fixation (plate or intramedullary fixation) at the recipient site, intraoperative and postoperative flap monitoring, and inpatient postoperative care with serial vascular checks and physical therapy planning. Typical length of stay is several days depending on flap viability and comorbidities. Typical site of service is the hospital operating room with inpatient postoperative care; this procedure may also occur at an ambulatory surgical center only in highly selected, low-risk cases but is most commonly performed in tertiary care hospitals with microsurgical teams.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when reporting only the surgeon's professional portion distinct from technical services (rare for this code). |
50 | Bilateral procedure | Use when identical vascularized fibular grafts are performed bilaterally (uncommon). |
51 | Multiple procedures | Use when reporting 20955 along with additional distinct procedures during the same operative session. |
52 | Reduced services | Use when the vascularized graft is partially performed or aborted with reduced work. |
53 | Discontinued procedure | Use if the procedure is started but terminated for patient safety before completion. |
54 | Surgical care only | Use when another clinician provides pre- and post-operative care and the reporting surgeon only performed the operation. |
55 | Postoperative management only | Use when the reporting surgeon only managed postoperative care after another surgeon performed the operation. |
62 | Two surgeons | Use when co-surgeons of different specialties concurrently perform distinct surgical components (e.g., orthopedics and plastic surgery). |
78 | Unplanned return to OR | Use when the patient returns to the OR for a related procedure during the global period (e.g., flap revision). |
79 | Unrelated procedure or service during the postoperative period | Use when an unrelated procedure is performed during the global period. |
22 | Increased procedural services | Use when documentation supports substantially greater work or complexity (extensive dissection, tumor resection with reconstruction). |
63 | Procedure performed on infant less than 4 kg | Use when applicable for neonatal patients meeting weight criteria. |
AS | Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery | Use when an assistant from advanced practice providers participates and reporting is required by payor rules. |
LT | Left side | Use to designate laterality when relevant to payer adjudication. |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
| 207L00000X | Orthopedic Surgery | Orthopedic surgeons commonly perform recipient site reconstruction and fixation. |
| 2080P0208X | Plastic and Reconstructive Surgery | Microsurgeons perform flap harvest and microvascular anastomosis. |
| 173P00000X | Surgery — Hand (relevant microsurgical expertise) | Hand/upper extremity surgeons with microsurgery training may perform similar transfers for limb salvage. |
| 207RH0000X | Surgery — Trauma | Trauma surgeons in tertiary centers may coordinate care for complex post-traumatic reconstructions. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
M84.16 | Pathological fracture, tibia | Segmental bone loss or pathological fracture may necessitate vascularized bone graft for reconstruction. |
S82.201A | Unspecified fracture of shaft of tibia, right leg, initial encounter for closed fracture | High-energy tibial shaft fractures with bone loss may require vascularized fibular grafting. |
M85.8 | Other specified disorders of bone density and structure | Disorders causing large defects or nonunion may be indications for vascularized graft. |
T79.A11 | Traumatic compartment syndrome of right lower leg | Severe soft-tissue injury with ischemia can accompany fractures requiring composite reconstruction. |
M84.10 | Pathological fracture, unspecified tibia and fibula | Pathologic bone loss leading to nonunion or large defects addressed with vascularized graft. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
15738 | Muscle, myocutaneous, or fasciocutaneous free flap with microvascular anastomosis | May be performed concurrently when soft-tissue coverage is required in addition to bony reconstruction. |
20956 | Vascularized osteocutaneous flap (including harvest of soft tissue component) | Closely related when the fibular transfer includes a skin paddle for composite reconstruction. |
27506 | Open treatment of tibial fracture, with or without internal or external fixation, with bone grafting | Performed before or during reconstruction to provide fixation of the recipient site when reconstructing long-bone defects. |
36415 | Collection of venous blood by venipuncture | Performed preoperatively for labs; listed here as a common ancillary service in perioperative workflow. |
69990 | Microsurgical techniques, requiring use of operating microscope | Billed adjunctively when use of an operating microscope for microvascular anastomosis is reported and allowed by payer. |