Surgical harvest and placement of a composite graft composed of dermis, fat, fascia, or a combination of those tissue layers from a donor site to a recipient site.

Verified May 8, 2026 · 6 sources ↓

Medicare: $606.23
Total RVUs: 18.15
Global, days: 90
Region: General

Drawn from CMSBedrockbillingCgsmedicareKzanowAAPC

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Identify all tissue layers harvested (dermis, fat, fascia) — document at least two layers to support 15770 over 20926
Specify the donor site anatomy and dimensions of tissue harvested
Describe the recipient site, including the defect size, etiology, and how the graft was inset and secured
State the medical necessity — e.g., post-tumor resection defect, traumatic tissue loss, congenital defect — with supporting diagnosis codes
Confirm that the primary procedure's code descriptor does not already include graft procurement, to justify separate reporting

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 51 Multiple procedures 52 Reduced services 59 Distinct service 76 Repeat, same physician 78 Unplanned return — related 79 Unrelated during global LT Left side RT Right side XS Separate structure

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 15770 covers a composite tissue graft — meaning at least two tissue layers (dermis, fat, and/or fascia) are harvested together and sutured into a recipient defect. That multi-layer requirement is the key distinction: if only fat is harvested, report 20926 instead. If only one layer is transferred, 15770 is the wrong code and will draw scrutiny.

The procedure appears across reconstructive contexts — post-oncologic defects, trauma, congenital deformities, and prior-surgery tissue loss — which explains why it surfaces in otolaryngology, podiatry, and orthopedic surgery billing. The 90-day global period means the harvest site management, routine recipient-site wound care, and standard follow-up visits through day 90 are all bundled. Unrelated problems billed in that window require modifier 24 or 25.

CMS NCCI policy creates an important bundling rule: if the primary procedure's code descriptor already includes procurement of a graft, 15770 cannot be reported separately. The same policy states that if any other HCPCS/CPT code more precisely describes the graft, 15770 yields to that more specific code. NCCI shows 15770 bundled as a component code under 26121 and 26123 with a modifier indicator of 1, meaning modifier 59 or an X-modifier can permit separate billing when the documentation supports a distinct site or service.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	8.74
Practice expense RVU	8
Malpractice RVU	1.41
Total RVU	18.15
Medicare national rate	$606.23
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	$606.23
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 15770 get rejected.

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

Single-layer harvest coded as 15770 — payer or audit downcodes to 20926 when only fat or only fascia is documented
Bundling denial when the primary procedure's descriptor includes tissue graft procurement, and no distinct-service modifier was appended
Unbundling flag when 15770 is billed with 26121 or 26123 without modifier 59 or XS to justify separate reporting
Lack of documented recipient-site defect dimensions or graft inset technique, leading to medical necessity denial
Global period conflict — post-op visits or related wound care billed separately within the 90-day global without modifier 24

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 6 cited references ↓

01What makes 15770 different from 20926?

15770 requires a composite harvest — at least two tissue layers (e.g., fat plus fascia, or dermis plus fat). 20926 covers single-layer grafts such as fat alone. If your op note only documents fat harvest, bill 20926.

02Can 15770 be billed separately when the primary procedure already includes graft procurement?

No. CMS NCCI policy explicitly prohibits separate reporting of 15770 when the primary procedure's code descriptor already includes tissue graft procurement. Separate billing in that scenario will be denied and cannot be overridden with a modifier.

03How do you handle bilateral derma-fat-fascia grafts on the same date?

Use modifier 50 for bilateral procedures performed at symmetric anatomic sites. If the two grafts are at distinct, non-symmetric sites, modifier 59 or XS may be more appropriate than 50. Document both sites clearly in the operative note.

04Is 15770 separately reportable with 26121 or 26123?

NCCI lists 15770 as a component code bundled under 26121 and 26123 with modifier indicator 1, meaning a modifier can allow separate payment. Use modifier 59 or XS only if the graft site is genuinely distinct from the contracture release site and your documentation supports it.

05What does the 90-day global period include for 15770?

All routine follow-up at both donor and recipient sites, dressing changes, suture or staple removal, and standard wound care through day 90 are bundled. Unrelated E/M services in that window need modifier 24; related procedures staged or planned require modifier 58.

06Which specialties most commonly bill 15770?

Per CMS Physician Fee Schedule 2026 utilization data, otolaryngology leads, followed by podiatry and orthopedic surgery — reflecting its use in head-and-neck reconstruction, foot defect repair, and post-oncologic or trauma reconstruction respectively.

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 specific tissue layers harvested (dermis, fat, fascia), donor and recipient site locations, defect dimensions, and graft inset method directly from dictation. That detail prevents the most common 15770 audit flag — an operative note that documents only one tissue layer, triggering a downcode to 20926 or an outright denial for insufficient composite-graft documentation.

See how Mira captures CPT 15770 documentation