Excision or curettage of a bone cyst or benign tumor of the femur, with allograft reconstruction of the defect.

Verified May 8, 2026 · 6 sources ↓

Medicare: $696.74
Work RVU: 9.84
Global, days: 90
Region: Knee

Drawn from CMSAbosAAPCFindacodeMdclarity

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Confirm graft type as allograft (not autograft or no graft) — the operative note must state this explicitly
Document lesion location within the femur (diaphysis, metaphysis, distal femur, etc.)
Include pre-operative imaging (X-ray, MRI, or CT) confirming the cystic or benign tumor diagnosis
Record lesion dimensions and the curettage or excision technique used
Document allograft source, lot number, and preparation used to fill the defect
Post-operative pathology report confirming benign histology to support medical necessity

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 24 Unrelated E/M during global 50 Bilateral procedure 51 Multiple procedures 59 Distinct service 76 Repeat, same physician 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 27356 describes surgical removal or curettage of a bone cyst or benign tumor from the femur, where the resulting osseous defect is filled using allograft bone. This distinguishes it from 27355 (excision alone, no graft) and 27357 (autograft, which includes graft harvest). The allograft is obtained from a tissue bank — graft harvest is not a component of this code. If internal fixation is also performed, add-on code 27358 is reported in addition to 27356.

The 90-day global period covers the operative session plus all routine post-op care through day 90. E&M services related to the lesion are bundled; use modifier 24 for unrelated office visits within the global window, or modifier 78 if the patient returns to the OR for a related complication. Laterality modifiers LT and RT are standard — bill a single line with modifier 50 for bilateral femoral lesions in a professional fee setting; ASC claims require two lines with LT and RT.

Documentation must support the benign or cystic nature of the lesion and confirm allograft use. Pathology is expected post-excision; its absence can trigger payer audit or medical necessity denial. Coders often confuse 27356 (allograft) with 27357 (autograft) — the operative note must explicitly name the graft source.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU vs. total RVU

The work RVU (9.84) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (20.86) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	9.84
Practice expense RVU	8.93
Malpractice RVU	2.09
Total RVU	20.86
Medicare national rate	$696.74
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	$696.74
HOPD (APC 5115) Hospital outpatient department	$13,116.76
ASC (PI J8) Ambulatory surgical center (freestanding)	$8,621.29

Common denial reasons

The recurring reasons claims for CPT 27356 get rejected.

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

Graft type not documented — payer cannot distinguish 27356 (allograft) from 27355 (no graft) or 27357 (autograft)
Missing or non-matching ICD-10 diagnosis — benign bone tumor or cyst code required; malignant lesion diagnoses map to different procedure codes
No pre-operative imaging in the record to support medical necessity of surgical intervention
Duplicate billing conflict when 27358 is appended without a separately documented primary procedure code
Global period violation — post-op E&M billed without modifier 24 when visit is unrelated to the femoral lesion

Frequently asked questions

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

01What is the difference between 27355, 27356, and 27357?

27355 is excision or curettage with no graft. 27356 adds allograft (donor bone). 27357 adds autograft — and includes the graft harvest in the code work. Use the one matching what was actually placed; the operative note must state graft source clearly.

02When do I add 27358 to 27356?

27358 is an add-on code for internal fixation performed at the same session as the primary excision. List 27358 in addition to 27356 when hardware is placed to stabilize the defect. 27358 cannot be billed alone.

03Is 27356 bilateral procedure-eligible, and how do I bill it?

Yes. For professional fee claims, report one line with modifier 50. For ASC claims, report two lines — one with LT and one with RT — each with one unit of service, per NCCI billing requirements.

04What ICD-10 codes support medical necessity for 27356?

Benign bone neoplasms (D16.2x for femur) and bone cyst codes (M85.5x series for aneurysmal bone cyst, M85.6x for solitary bone cyst) are the primary supporting diagnoses. Malignant lesion codes route to different procedure codes and will trigger a mismatch denial.

05Can I bill an E&M on the same day as 27356?

Only if the E&M is significant, separately identifiable, and unrelated to the decision to perform the excision. Append modifier 25 to the E&M. The decision to perform the surgery itself is included in the surgical payment and is not separately billable.

06What happens if the patient returns to the OR within the 90-day global for a wound complication?

Bill the return procedure with modifier 78 (unplanned return to the OR for a related procedure within the global period). If the return is for an entirely unrelated condition, use modifier 79 instead.

07Is pathology required to bill 27356?

CMS does not mandate a separate pathology code to bill 27356, but payers routinely expect post-excision pathology confirming benign histology. Missing pathology is a common audit flag and can support a medical necessity denial on retrospective review.

Sources & references

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

Mira Scribe

Mira's AI scribe captures graft type (allograft vs. autograft), lesion location within the femur, lesion size, curettage versus excision technique, and whether internal fixation was placed — the detail that drives the 27356 vs. 27357 vs. 27358 distinction. Explicit graft-source language in the dictation prevents the most common denial: a payer downgrading 27356 to 27355 because the operative note never confirmed allograft use.

See how Mira captures CPT 27356 documentation