Intertrochanteric or subtrochanteric femoral osteotomy with internal or external fixation and/or cast application to correct deformity or malalignment in the proximal femur.

Verified May 8, 2026 · 6 sources ↓

Medicare: $1,259.55
Total RVUs: 37.71
Global, days: 90
Region: Hip

Drawn from CMSAAPCBedrockbilling

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Specify osteotomy level: intertrochanteric vs. subtrochanteric — the note must name the anatomic zone, not just 'proximal femur'.
Document the deformity or condition being corrected (e.g., coxa vara, malunion, congenital deformity, prior failed fixation) with supporting imaging.
Describe the fixation method used: blade plate, dynamic hip screw, intramedullary nail, external fixator, or cast — and confirm it is part of the same operative session.
Record the surgical approach by name and confirm which side (LT or RT) was operated — a note that says 'standard approach' will flag on audit.
If bone graft was harvested from a distant site or separate incision, document that separately to support add-on graft codes (e.g., 20900/20902).
Include intraoperative fluoroscopy use if applicable, noting that imaging guidance bundled into the surgical session is not separately billable.

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 52 Reduced services 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 6 cited references ↓

CPT 27165 covers an osteotomy of the femur at the intertrochanteric or subtrochanteric level — the bone is divided between or just below the trochanters to correct angular deformity, rotational malalignment, or limb-length discrepancy. The procedure inherently includes internal fixation (plate and screws, blade plate, intramedullary device), external fixation, or cast stabilization as needed; you don't bill those separately.

The code sits in the 90-day global period. That window covers the preoperative day, the operative session, and all routine follow-up through day 90. E/M visits for unrelated conditions in that window require modifier 24. Staged or unplanned return procedures need modifier 79 or 78, respectively.

This is an inpatient-only (status indicator J1) code under the OPPS. You cannot bill it on an outpatient facility claim; it routes to the inpatient DRG system. The HOPD and ASC payment figures displayed on this page reflect reference data only — the operative site for this procedure is the inpatient setting.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	19.78
Practice expense RVU	13.72
Malpractice RVU	4.21
Total RVU	37.71
Medicare national rate	$1,259.55
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	$1,259.55
HOPD (APC 5114) Hospital outpatient department	$7,413.38
ASC (PI J8) Ambulatory surgical center (freestanding)	$4,682.29

Common denial reasons

The recurring reasons claims for CPT 27165 get rejected.

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

Billed to outpatient facility: 27165 is inpatient-only (SI=J1) under OPPS — outpatient facility claims will be rejected at the status-indicator level.
Fixation method not documented: payers deny or downcode when the operative note omits which fixation device was used or implies it was a separate procedure.
Missing laterality modifier: Medicare and most commercial payers require LT or RT on unilateral procedures; absent modifier triggers automated denial.
Bone graft coded as bundled when harvested from a separate site: graft from the iliac crest or other distant site is separately billable with 20900/20902, but only if the note documents a distinct incision site.
Global period conflict: E/M billed within the 90-day global without modifier 24 (unrelated condition) will be denied as included in the surgical package.

Frequently asked questions

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

01Is 27165 payable in an ASC or outpatient hospital setting?

No. Under CMS OPPS, 27165 carries status indicator J1 (inpatient-only). Billing it on an outpatient facility claim will be denied. The procedure must be performed in the inpatient setting and billed through the DRG system.

02Can I separately bill bone graft when it's part of a 27165 procedure?

It depends on the graft source. Graft obtained from the local operative site is bundled into 27165. If graft is harvested from a separate incision or distant site — such as the iliac crest — codes 20900 or 20902 may be reported separately, provided the operative note documents the distinct harvest site and incision.

03How do I bill for hardware removal after a prior 27165?

Hardware removal performed after the 90-day global period is billed with modifier 79 (unrelated procedure during global) or as a new service after the global ends. If removal is done during the same operative session as the osteotomy, it is generally bundled. Check NCCI edits for the specific removal code pairing.

04What modifier applies if the surgeon performs an unplanned return to the OR for a complication related to 27165?

Modifier 78 applies when the return to the OR is for a complication or directly related reason within the global period. Modifier 79 is for an unrelated procedure during the global. Do not invert these — misuse is a common audit finding.

05Can 27165 and 27134 (revision THA) be billed on the same day?

Same-day billing of 27165 with a hip arthroplasty code is uncommon and scrutinized. NCCI edits and clinical context determine payability. If both procedures are genuinely distinct and medically necessary, append modifier 51 to the lower-value code and ensure documentation clearly describes each procedure's separate indication and operative steps.

06Does the 90-day global period affect post-op physical therapy billing?

The global period affects physician billing only, not therapy services billed by a separate PT provider. However, if the operating surgeon's practice bills E/M or other physician services within 90 days, those require modifier 24 if unrelated or are included in the global if routine post-op.

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 osteotomy level (intertrochanteric vs. subtrochanteric), the specific fixation construct applied, operative laterality, and the clinical indication driving the correction. It flags when the note references a 'standard approach' without naming it, and confirms whether bone graft was taken from a separate incision site — the two most common audit triggers on 27165 claims.

See how Mira captures CPT 27165 documentation