Bone grafting of the femoral head, neck, intertrochanteric, or subtrochanteric area, including harvest of the autograft from the patient's own body.

Verified May 8, 2026 · 5 sources ↓

Medicare: $1,065.15
Total RVUs: 31.89
Global, days: 90
Region: Hip

Drawn from CMSGenhealthEmednyAAPC

Documentation requirements

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

Source · Editorial brief grounded in 5 cited references ↓

Specific anatomic zone treated — femoral head, neck, intertrochanteric, or subtrochanteric — named explicitly in the operative note
Graft type and source: autograft with donor site identified (e.g., iliac crest) or allograft with description
Clinical indication for grafting (e.g., AVN stage, nonunion, structural defect) with supporting imaging reference
Description of graft preparation, shaping, and placement technique
Any internal fixation used to stabilize the graft, including hardware type and location
Pre-op and post-op diagnoses documented and consistent with the ICD-10 code billed

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 25 Significant separate E/M 51 Multiple procedures 57 Decision for surgery 58 Staged or related 62 Co-surgeons 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 5 cited references ↓

CPT 27170 covers open surgical bone grafting to the proximal femur — specifically the femoral head, neck, intertrochanteric, or subtrochanteric zones. The code bundles graft harvest into the procedure; you cannot separately bill 20900-series graft harvest codes when 27170 is on the claim. Typical indications include avascular necrosis (AVN) of the femoral head, nonunion of femoral neck fractures, and structural defects in the proximal femur that require biologic augmentation to achieve healing.

The 90-day global period applies. That window covers the surgery date, the day-before pre-op visit, and all routine post-op care through day 90. Unrelated E/M visits in that window require modifier 24; same-day E/M prior to the decision for surgery needs modifier 57 if the decision was made that day at a major-surgery level. If internal fixation is placed to stabilize the graft, confirm with your payer whether a separate fixation code is payable — NCCI edits may bundle it, and payer policy varies.

This procedure sits in the hip reconstruction family alongside hemiarthroplasty (27125) and total hip arthroplasty (27130). If the clinical picture has progressed to the point where prosthetic replacement is performed instead of grafting, 27170 is the wrong code. Document the specific anatomic zone treated (head, neck, intertrochanteric, subtrochanteric) and the graft source (autograft donor site location or allograft) to withstand audit scrutiny.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	17.17
Practice expense RVU	11.07
Malpractice RVU	3.65
Total RVU	31.89
Medicare national rate	$1,065.15
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	$1,065.15
HOPD (APC 5114) Hospital outpatient department	$7,413.38
ASC (PI J8) Ambulatory surgical center (freestanding)	$4,822.66

Common denial reasons

The recurring reasons claims for CPT 27170 get rejected.

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

Separate billing of bone graft harvest codes (20900-20924) alongside 27170 — harvest is bundled per NCCI policy
Wrong code selection when a prosthetic replacement was actually performed — payers recode to 27125 or 27130
Missing or vague documentation of the specific femoral zone treated, triggering medical necessity denials
Global period conflict when a same-day E/M is billed without modifier 25 or a post-op visit is billed without modifier 24
Lack of pre-operative imaging (X-ray or MRI) in the record to support the structural diagnosis requiring grafting

Frequently asked questions

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

01Is bone graft harvest billed separately with 27170?

No. The code descriptor explicitly includes obtaining the bone graft. Separately billing 20900-series harvest codes with 27170 violates NCCI bundling rules and will be denied.

02Can internal fixation placed to stabilize the graft be billed separately?

This is payer-variable. NCCI edits may bundle stabilization hardware into 27170. Query your MAC or check NCCI PTP tables before billing a separate fixation code — and document the fixation distinctly in the operative note if you intend to bill it.

03What modifier applies to an E/M visit on the same day as 27170?

Use modifier 25 if a separately identifiable E/M was performed the same day. Use modifier 57 if the E/M was the visit at which the decision for this major surgery was made, and it occurred the day of or the day before the procedure.

04How does 27170 differ from 27125 or 27130?

27170 is biological grafting to preserve the native femoral head. 27125 is partial (hemi) arthroplasty replacing the femoral head with a prosthesis. 27130 is total hip arthroplasty replacing both the femoral head and acetabulum. If implants are placed, 27170 is not the right code.

05What ICD-10 codes most commonly pair with 27170?

Avascular necrosis of the femoral head (M87.05x, M87.15x), femoral neck nonunion (M84.35x), and structural bone defects of the proximal femur are the primary indications. The diagnosis must be supported by pre-operative imaging in the record.

06Does the 90-day global period affect how post-op fracture complications are billed?

Yes. A return to the OR for a complication related to the graft or the original procedure bills with modifier 78 (unplanned return, related). An unrelated procedure performed during the global window uses modifier 79. Do not invert these.

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 femoral zone grafted (head, neck, intertrochanteric, or subtrochanteric), graft source and harvest site, fixation hardware if placed, and the operative indication from dictation. That specificity prevents the two most common 27170 audit flags: a vague anatomic description and an unbundled graft harvest code appearing on the same claim.

See how Mira captures CPT 27170 documentation