Surgical · Knee

Surgical lengthening of the femur (thigh bone) via osteoplasty, typically using osteodistraction to gradually separate bone segments and stimulate new bone formation across the gap.

Verified May 8, 2026 · 6 sources ↓

Medicare: $1,369.44
Total RVUs: 41
Global, days: 90
Region: Knee

Drawn from CMSNuvasiveAAPCCgsmedicareSciencedirect

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Operative note must identify the specific osteotomy site and technique (e.g., corticotomy at femoral shaft, percutaneous vs. open approach) — 'standard approach' is an audit flag.
Document the indication driving lengthening: measured limb length discrepancy with pre-op imaging, congenital deformity diagnosis, or other structural etiology with supporting ICD-10.
Specify fixation method used: external fixator frame, intramedullary lengthening nail (and model/implant), or combined — this determines whether a separate implant insertion code is billable.
Record the planned distraction rate and frequency (mm/day, number of daily adjustments) to support medical necessity for the lengthening protocol.
Pre-operative standing full-length AP radiographs or CT scanograms documenting the magnitude of discrepancy — payers frequently require these as prior auth support.
If nail insertion is billed separately, the operative note must clearly describe nail insertion as a distinct procedural step with its own instrumentation sequence.

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 50 Bilateral procedure 51 Multiple procedures 58 Staged or related 59 Distinct service 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 27466 covers femoral osteoplasty performed specifically for lengthening — most commonly to correct limb length discrepancy (LLD) or congenital deformity. The operative technique typically involves a corticotomy or osteotomy, followed by gradual distraction using an external fixator or an intramedullary lengthening nail (e.g., PRECICE system). New bone fills the distraction gap over weeks to months in a process called distraction osteogenesis. The 90-day global period attaches to this code, covering all routine post-op management, device adjustment visits, and follow-up imaging interpretation through day 90.

A critical coding distinction: 27466 covers the osteoplasty itself. Insertion of an intramedullary lengthening nail is a separately reportable procedure — PRECICE device representatives and AAPC forum guidance both confirm that the nail insertion is not bundled into 27466 and should be reported with the appropriate IM nail insertion code when performed. Verify NCCI PTP edits for the specific nail code you intend to pair before billing. Modifier 51 applies when reporting multiple procedures in the same session.

For bilateral femoral lengthening — rare but performed in certain skeletal dysplasia cases — append modifier 50. If the contralateral femur is addressed in a staged second surgery during the global period and the indication is related, modifier 58 applies. Unrelated procedures during the 90-day global need modifier 79.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	22.08
Practice expense RVU	14.21
Malpractice RVU	4.71
Total RVU	41
Medicare national rate	$1,369.44
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	$1,369.44
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 27466 get rejected.

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

Medical necessity denial when pre-op imaging documenting measurable limb length discrepancy is absent from the record or not submitted with the claim.
Bundling denial when the intramedullary nail insertion code is billed alongside 27466 without NCCI PTP review and an appropriate modifier — verify column 1/2 status before billing the combination.
Missing or invalid prior authorization — femoral lengthening is a high-cost elective procedure and most commercial payers require auth; auth number absent on claim triggers automatic denial.
Global period violation when post-op outpatient E/M visits during the 90-day window are billed without modifier 24 (unrelated) or 25 (same-day significant separate service).
Laterality ambiguity on claims for unilateral procedures — append LT or RT; claims with no laterality indicator are frequently rejected by commercial payers.

Frequently asked questions

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

01Does 27466 include insertion of an intramedullary lengthening nail like the PRECICE?

No. The osteoplasty code covers the bone-cutting and lengthening work, not nail insertion. The intramedullary nail insertion is separately reportable. Check NCCI PTP edits for the specific IM nail code before billing both on the same date, and append modifier 51 if unbundling is supported.

02What is the global period for 27466?

90 days. All routine post-op visits, device adjustment visits, and related outpatient care through day 90 are included. Bill E/M visits during the global only with modifier 24 (unrelated condition) or modifier 25 (same-day significant separate service with a distinct reason).

03Can 27466 be billed bilaterally?

Yes, when both femurs are lengthened in the same operative session. Append modifier 50. If the second side is done in a planned staged procedure during the global period, use modifier 58 instead — that signals a staged related procedure, which reopens a new global.

04How does 27466 differ from 27468?

27466 is lengthening only. 27468 covers a combined procedure: lengthening one femoral segment while simultaneously shortening another with a segment transfer. Use 27468 when both maneuvers are performed in the same operative session. They are not interchangeable.

05What ICD-10 codes typically pair with 27466?

Most claims use M21.751–M21.752 (limb length inequality, femur) or Q72-series congenital reduction defects of lower limb. Payers cross-check the diagnosis against the stated discrepancy measurement in the record — a vague or missing ICD-10 is a common denial trigger.

06Is prior authorization required for 27466?

For most commercial payers, yes — femoral lengthening is classified as a high-cost elective surgical procedure. Medicare does not require prior auth for this code under standard FFS, but Advantage plans vary. Confirm auth requirements before scheduling and include the auth number on the claim.

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 corticotomy or osteotomy site, fixation construct (external frame vs. intramedullary nail with model), distraction protocol, and the measured limb length discrepancy from pre-op imaging — all from surgeon dictation. That prevents the two most common audit flags on 27466: operative notes that omit fixation detail (triggering bundling disputes over separate nail codes) and records with no documented LLD measurement to anchor the medical necessity argument.

See how Mira captures CPT 27466 documentation