Billing code 20956: Bone graftMedicare rate & RVUs

Medicare pays $2,355.43 for 20956 nationally in a facility.

Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.

What 20956 covers

The surgeon harvests bone from the iliac crest with its blood supply and connects the graft’s vessels to recipient vessels using microsurgical technique. This vascularized bone transfer can rebuild a defect where living bone is needed, such as mandibular reconstruction after tumor removal or reconstruction of a major bone defect. Plastic, oral and maxillofacial, or orthopedic surgeons may perform the procedure in an operating room, often as part of a larger reconstruction.

Select this code when the graft is iliac bone and the procedure includes microvascular anastomosis; the donor bone site and vascular technique distinguish it from other graft codes. The operative report should identify the iliac donor site, graft transfer, vascular anastomosis, and reconstructive purpose. CMS assigns a 90-day global period, including the day-before preoperative visit and 90 days of related postoperative care. For multiple procedures in one session, the highest-valued procedure is paid in full and others at 50%. Modifier 50 is inappropriate. Assistant-at-surgery payment may be available; co-surgeon payment requires supporting documentation, and team surgery is not permitted.

This summary was written with AI assistance from CMS physician fee schedule data and checked against the CMS billing rules shown here. Rates on this page come directly from CMS files.

Where 20956 pays more and less

The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.

109 of 109 payment localities

20956 rates by state

Office rate range in each state. Select a state to see its payment localities.

How the 20956 rate is calculated

Each of 20956’s three RVUs is multiplied by a geographic index (GPCI) for the payment locality, added up, and multiplied by the conversion factor. Drag the indexes or enter a ZIP to see what moves the rate.

Payment rules and modifiers for 20956

20956 has a 90-day global period: related visits in that window are included in the surgery payment.

What modifiers do to the payment

When to use modifier 51

20956 compared with similar codes

How to choose

20955Bone graft

Both describe microvascular bone grafting, but 20955 identifies the fibula as the donor site; this code identifies iliac bone.

20957Bone graft

Use 20957 for a metatarsal donor graft. The donor bone site, not the general microvascular technique, separates it from this code.

20962Bone graft

This code is specific to iliac bone; 20962 is the family option for a microvascular bone graft from another donor site.

20970Bone and skin graft

20970 describes an iliac-crest bone-and-skin graft. This code is for the microvascular iliac bone graft without that bone-and-skin distinction.

Codes related to 20956

Related codes aren’t interchangeable: bill the code that matches the service performed.

Where these rates come from

FeeBase calculates base physician payments from CMS work, practice-expense and malpractice RVUs, adjusted by each locality’s geographic indexes and the conversion factor. Services without a published rate are labeled, never given a made-up amount. Amounts are Medicare allowed amounts before claim adjustments: not a patient’s bill or a commercial rate.

CMS RVU26D · effective Oct 1, 2026 through the day before Jan 1, 2027

Open CMS sourceHow we calculate rates