20972

Free osteocutaneous flap transfer from a metatarsal donor site, with microvascular anastomosis, to reconstruct a recipient site requiring both bone and skin coverage.

Verified May 8, 2026 · 5 sources ↓

Medicare: $2,531.79
Total RVUs: 75.8
Global, days: 90
Region: Foot & ankle

Drawn from CMSAAPCEmedny

Documentation requirements

What must appear in the operative or office note to support the claim.

Source · Editorial brief grounded in 5 cited references ↓

Operative note must identify the metatarsal as the specific donor site by name and number (e.g., second metatarsal).
Document the vascular pedicle dissection and microvascular anastomosis technique, including vessel(s) anastomosed and patency confirmation.
Document the skin paddle dimensions harvested with the flap and the soft-tissue defect it addresses at the recipient site.
Describe the osseous defect at the recipient site — size, etiology (trauma, tumor, necrosis), and why local bone grafting was insufficient.
Record intraoperative Doppler or clinical confirmation of flap perfusion post-anastomosis.
Preoperative imaging or surgical oncology/trauma records documenting the extent of bone and soft-tissue loss should be in the chart to support medical necessity.

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 51 Multiple procedures 58 Staged or related 59 Distinct service 62 Co-surgeons 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon AS PA/NP/CNS assistant LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 5 cited references ↓

CPT 20972 describes harvesting a free osteocutaneous flap from a metatarsal — bone with its intact vascular pedicle and an attached skin paddle — and transferring it to a recipient site via microvascular anastomosis. The procedure addresses defects that require simultaneous osseous and soft-tissue reconstruction, typically resulting from trauma, tumor resection, or avascular necrosis where local tissue options are inadequate.

This is a high-complexity microsurgical procedure with a 90-day global period. That global covers the operative day, the day-before pre-op visit, and all routine follow-up through day 90. Any unrelated procedure billed during that window requires modifier 79; a staged, related return to the OR requires modifier 58. Because this code bundles the flap harvest and the microvascular inset into a single reportable unit, do not separately report the donor-site closure or vascular anastomosis — those are integral to the work described.

Site of service matters significantly here. HOPD and ASC payment rates differ; see the Site of Service comparison table. Payers vary on whether prior authorization is required for free-flap reconstruction and on acceptable ICD-10 linkages — confirm diagnoses that document both the osseous defect and the soft-tissue loss to support medical necessity for an osteocutaneous (rather than bone-only) graft.

RVU & reimbursement

Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	43.4
Practice expense RVU	23.14
Malpractice RVU	9.26
Total RVU	75.8
Medicare national rate	$2,531.79
Global period	90 days

Payment by site of service

Medicare pays different rates by setting. HOPD typically pays substantially more than ASC for the same procedure.

Source · CMS OPPS Addendum B·ASC HCPCS payment rates·2026

Setting	Medicare rate (national)
Office (PFS non-facility) Procedure performed in physician's office	$2,531.79
HOPD (APC 5114) Hospital outpatient department	$7,413.38
ASC (PI G2) Ambulatory surgical center (freestanding)	$3,695.53

Common denial reasons

The recurring reasons claims for CPT 20972 get rejected.

Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓

Medical necessity not established — ICD-10 codes document only bone loss without also capturing the soft-tissue defect that justifies an osteocutaneous versus bone-only graft.
Operative note fails to describe microvascular anastomosis, leading payers to question whether a free-flap or a simpler pedicled graft was performed.
Separate billing of donor-site closure or vascular anastomosis alongside 20972, triggering NCCI bundling edits.
Missing prior authorization for free-flap reconstruction when required by the commercial or managed-care payer.
Global period violations — a related post-op procedure billed without modifier 58 or 78 during the 90-day window.

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 5 cited references ↓

01What distinguishes 20972 from 20957?

CPT 20957 is a bone graft with microvascular anastomosis from the metatarsal — bone and vessels only. CPT 20972 is a free osteocutaneous flap, meaning it includes a skin paddle harvested with the bone. Use 20972 only when skin coverage at the recipient site is part of the reconstructive goal.

02Can I bill the donor-site closure separately?

No. Donor-site closure is integral to the flap harvest and is not separately reportable with 20972. Billing it separately will trigger NCCI bundling edits.

03What modifier applies if the patient returns to the OR within the 90-day global for a related complication?

Use modifier 78 for an unplanned return to the operating room for a procedure related to the original surgery during the global period — for example, returning to revise the anastomosis for flap compromise.

04What modifier applies for a staged second procedure planned at the time of the original surgery?

Use modifier 58 when the return to the OR was planned or staged at the time of the original procedure, or when the second procedure is more extensive than the original.

05Which ICD-10 diagnoses best support medical necessity for 20972 versus a simpler bone graft?

You need codes that document both the osseous defect and concurrent soft-tissue loss or coverage deficiency — for example, an open fracture with soft-tissue loss, post-oncologic resection defect, or traumatic wound with exposed bone. A diagnosis capturing bone pathology alone is insufficient to justify an osteocutaneous flap and will commonly result in a downcode or denial.

06Is modifier 51 appropriate when 20972 is billed with another procedure on the same date?

Modifier 51 applies when 20972 is reported alongside another non-exempt surgical procedure in the same session. Confirm the second procedure is not already bundled into 20972 under NCCI edits before appending modifier 51 or 59.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

Mira AI Scribe

Mira's AI scribe captures the metatarsal donor-site number, skin paddle dimensions, vascular pedicle vessels, anastomosis technique, and intraoperative perfusion confirmation directly from the surgeon's dictation. It also flags when the operative note lacks explicit documentation of the soft-tissue defect at the recipient site — the most common reason payers downcode or deny 20972 to a bone-only graft code.

See how Mira captures CPT 20972 documentation