Muscle, myocutaneous, or fasciocutaneous flap procedure performed on the lower extremity, involving transfer of vascularized tissue to cover or reconstruct a defect in the leg region.

Verified May 8, 2026 · 7 sources ↓

Medicare: $1,148.32
Total RVUs: 34.38
Global, days: 90
Region: Foot & ankle

Drawn from CMSMdclarityFindacodeOpenpayerAAPC

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Specify flap type by name: muscle, myocutaneous, or fasciocutaneous — generic 'flap' is not sufficient for audit purposes.
Document the anatomic flap used (e.g., gastrocnemius, soleus, sural artery fasciocutaneous) and the recipient defect location on the lower extremity.
Record defect size in square centimeters before and after debridement or wound preparation.
Describe the vascular pedicle, flap dimensions, donor site management, and inset technique in the operative note.
If modifier 22 is appended, document specific factors increasing intraoperative complexity — unusual anatomy, prior failed coverage, radiation field, or prolonged operative time with explanation.
For co-surgeon billing with modifier 62, both operative notes must independently document distinct, non-overlapping portions of the procedure.

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 50 Bilateral procedure 51 Multiple procedures 59 Distinct service 62 Co-surgeons 76 Repeat, same physician 77 Repeat, another physician 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 15738 covers surgical creation and transfer of a muscle, myocutaneous, or fasciocutaneous flap to reconstruct a lower extremity defect. The flap remains attached to its native blood supply (pedicled) or is transferred with microsurgical revascularization. Common indications include coverage of open fractures, chronic wounds, post-oncologic resection defects, and infected hardware exposure in the tibia or distal leg — scenarios where skin grafting alone is insufficient.

This code sits within the 15570–15738 flap series and carries a 90-day global period. That means routine post-op flap monitoring visits, wound care, and suture removal through day 90 are bundled. Any E/M service during that window for a separate, unrelated problem requires modifier 24. A staged revision or secondary flap procedure planned at the time of the initial surgery requires modifier 58 and resets the global clock.

Debridement or surgical wound preparation performed immediately before flap inset is a common same-day bundling question. NCCI edits bundle standard wound prep with 15738; if the debridement is a separately identifiable, extensive service with its own documentation, modifier 59 (or an X-modifier) may be required to support separate billing. Confirm current NCCI edits before appending — payer interpretation varies.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	18.56
Practice expense RVU	12.2
Malpractice RVU	3.62
Total RVU	34.38
Medicare national rate	$1,148.32
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	$1,148.32
HOPD (APC 5055) Hospital outpatient department	$3,620.48
ASC (PI A2) Ambulatory surgical center (freestanding)	$1,940.78

Common denial reasons

The recurring reasons claims for CPT 15738 get rejected.

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

Bundling with same-day wound debridement codes (11042–11047 or 15002–15003) when separate documentation does not support a distinct service.
Missing or non-specific flap type in the operative note — payors and auditors require identification of the specific flap, not just 'flap closure'.
Global period violations: E/M or wound care visits billed without modifier 24 during the 90-day postoperative window.
Bilateral modifier 50 applied incorrectly when procedures were performed at different anatomic sites on the same leg rather than truly bilateral (both legs).
Modifier 22 appended without supporting documentation quantifying the increased work — documentation must justify the claim, not just assert complexity.

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 7 cited references ↓

01Can debridement be billed separately on the same day as 15738?

Only if the debridement is a distinct, separately documented service beyond routine surgical prep. NCCI bundles standard wound preparation with 15738. If the debridement is extensive and independently documented, modifier 59 may support separate billing — but verify current NCCI edits, as payer enforcement varies.

02What modifiers apply when two surgeons each perform distinct portions of the flap procedure?

Use modifier 62 (co-surgeons) when two surgeons perform distinctly different, non-overlapping parts — for example, one harvesting the flap while the other prepares the recipient site. Both surgeons bill 15738-62, and each must have an independent operative note documenting their specific work.

03Does 15738 carry a global period, and what does it include?

Yes — 90-day global. It covers the surgery day, all routine post-op visits, wound care, dressing changes, and suture removal through day 90. Unrelated E/M services in that window need modifier 24. A planned staged revision needs modifier 58, which resets the global clock.

04When is modifier 58 versus modifier 78 correct for a return to the OR after 15738?

Modifier 58 applies to a staged or planned related procedure — documented as intentional in the original operative note. Modifier 78 applies to an unplanned return to the OR for a complication or related problem arising during the global period. Using 78 when 58 is correct (or vice versa) is a common audit finding.

05Is 15738 appropriate for upper extremity flaps?

No. 15738 is specific to the lower extremity. Upper extremity muscle or fasciocutaneous flap procedures map to different codes in the 15730s series. Using 15738 for an upper extremity case will trigger a mismatch between the procedure code and the ICD-10 diagnosis code, resulting in denial.

06How does site of service affect reimbursement for 15738?

There is a material difference between HOPD and ASC payment rates for 15738 under CMS PFS 2026 — see the Site of Service comparison table on this page. The facility payment differential should factor into site-of-care planning for elective reconstructive cases.

Sources & references

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

Mira AI Scribe

Mira's AI scribe captures flap type (muscle, myocutaneous, or fasciocutaneous), named flap (e.g., gastrocnemius, soleus), defect location and dimensions in cm², donor site management, and vascular pedicle description directly from surgeon dictation. This prevents the single most common audit flag on 15738: an operative note that documents a flap procedure without specifying the flap by anatomic name and tissue composition.

See how Mira captures CPT 15738 documentation