Surgical · Knee

Femoral osteotomy performed with insertion and management of an externally controlled intramedullary lengthening device for limb-length discrepancy correction.

Verified May 8, 2026 · 5 sources ↓

Medicare: $1,731.50
Total RVUs: 51.84
Global, days: 90
Region: Knee

Drawn from AdscFindacodeCMSFederalregister

Documentation requirements

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

Source · Editorial brief grounded in 5 cited references ↓

Quantified limb-length discrepancy with measurement method (e.g., full-length standing radiograph with calibration marker)
Operative note specifying osteotomy site, technique, and named intramedullary lengthening device inserted
Medical necessity rationale explaining why surgical lengthening is indicated over observation or shoe-lift management
Device adjustment schedule or lengthening protocol documented in the medical record
Pre-operative imaging confirming deformity and alignment to support procedure planning
Diagnosis code(s) linking limb-length discrepancy etiology (congenital, post-traumatic, oncologic, etc.) to the procedure

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 52 Reduced services 57 Decision for surgery 58 Staged or related 59 Distinct service 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 27458 is a new code for 2026 covering femoral osteotomy combined with insertion of an externally controlled intramedullary lengthening device. The code is all-inclusive: the osteotomy, the implant itself, and management of the adjustment schedule are all bundled into a single reportable unit. It was introduced alongside 27713 (tibial equivalent) to replace previous patchwork coding approaches for motorized intramedullary lengthening procedures.

Billing 27458 with 27450, 27466, 27470, 27472, or 27506 is a hard bundling conflict — those codes cannot be reported on the same claim. The 90-day global period means all routine post-operative management, device adjustment visits, and follow-up imaging integral to the lengthening protocol are non-separately billable through day 90. Unrelated problems presenting during the global require modifier 24 on the E/M; a staged or related subsequent procedure requires modifier 58.

This code applies to skeletally immature and mature patients undergoing femoral lengthening for limb-length discrepancy. Medical necessity documentation must establish the magnitude of discrepancy, failure or inappropriateness of conservative management, and the specific device used. Payers vary on whether prior authorization is required; confirm with each commercial plan before scheduling.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	26.65
Practice expense RVU	20.06
Malpractice RVU	5.13
Total RVU	51.84
Medicare national rate	$1,731.50
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	$1,731.50
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 27458 get rejected.

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

Bundling conflict when 27458 is billed alongside 27450, 27466, 27470, 27472, or 27506 on the same claim
Missing prior authorization for commercial or Medicaid payers that require it for intramedullary lengthening implants
Insufficient medical necessity documentation — payers require quantified LLD measurement and clinical justification, not just a diagnosis code
Post-operative device adjustment visits billed separately during the 90-day global without modifier 24 or 58 to override bundling
Incorrect or missing diagnosis code pairing; unspecified limb-length discrepancy without laterality triggers payer edits

Frequently asked questions

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

01Is 27458 really all-inclusive, or can I separately bill for the lengthening device hardware?

27458 bundles the osteotomy, implant insertion, and management of the adjustment schedule into one code. The device cost is not separately billable under the physician fee schedule. Facility charges for the implant are handled on the facility side under OPPS or ASC payment rules.

02Can I bill 27458 and 27713 together if I perform femoral and tibial lengthening in the same session?

Yes, if both a femoral and tibial osteotomy with intramedullary lengthening device are performed in the same operative session, you can report both codes. Append modifier 51 to the secondary procedure. Document each osteotomy site distinctly in the operative note.

03What happens to device adjustment visits during the 90-day global?

Routine adjustment visits integral to the lengthening protocol are included in the global and are not separately billable. If a visit addresses a complication or a new, unrelated problem, use modifier 78 for an unplanned related return to the OR or modifier 24 on an E/M for an unrelated problem in the office.

04Which codes are hard bundling conflicts with 27458?

Per 2026 AMA CPT guidance, 27458 cannot be billed with 27450, 27466, 27470, 27472, or 27506. Attempting to report any of these on the same claim will generate an NCCI edit denial without an applicable modifier override.

05Does 27458 require prior authorization, and does that differ by payer?

Medicare does not have a standing prior authorization requirement for 27458, but many commercial payers and some state Medicaid programs do require authorization for intramedullary lengthening procedures. Verify with each plan before scheduling — failure to obtain auth is a clean denial with no appeal pathway once the surgery is done.

06What diagnosis codes typically support 27458?

Limb-length discrepancy ICD-10 codes (e.g., M21.7x series) are the primary supporting diagnoses. Document laterality and etiology — congenital, post-traumatic, oncologic, or post-infectious — because payers use that specificity in medical necessity review.

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 named intramedullary lengthening device, the osteotomy site and technique, the quantified limb-length discrepancy, and the planned adjustment protocol directly from dictation. That prevents the most common denial trigger for 27458: operative notes that confirm a lengthening procedure was performed but omit the specific device and LLD measurement auditors need to validate medical necessity.

See how Mira captures CPT 27458 documentation