Open surgical arrest of the distal fibular epiphysis (epiphysiodesis) to correct or prevent limb-length discrepancy in skeletally immature patients.

Verified May 8, 2026 · 6 sources ↓

Medicare: $441.89
Total RVUs: 13.23
Global, days: 90
Region: Foot & ankle

Drawn from CMSFastrvuRvuedgeEmedny

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Skeletal age confirmed by bone age radiograph (hand/wrist X-ray with radiologist read), not chronological age alone
Predicted leg-length discrepancy at skeletal maturity, with the calculation method documented (e.g., Moseley straight-line graph, multiplier method)
Operative note specifying open approach, confirmation of distal fibular physis identification, and method of epiphyseal arrest
Laterality clearly stated — left, right, or bilateral — in both the pre-op note and operative report
Indication distinguishing this from fracture care: growth modulation, not acute physeal injury repair
Post-op plan for limb-length monitoring, including anticipated follow-up imaging schedule

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 62 Co-surgeons LT Left side RT Right side 80 Assistant surgeon AS PA/NP/CNS assistant

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 27732 describes open epiphysiodesis of the distal fibula — a procedure performed on growing patients to permanently arrest physeal growth at that site. The clinical indication is typically a leg-length discrepancy or angular deformity where controlled growth arrest of the fibular physis will allow the contralateral extremity to catch up, or where asymmetric fibular growth is contributing to ankle valgus. The procedure is distinct from fracture repair; it is a deliberate, planned growth-modulation surgery.

The 90-day global period covers all routine post-op management through day 90, including follow-up imaging visits used to monitor limb-length progression. Any E&M visit for a new or unrelated problem during that window requires modifier 24. If a staged contralateral or additional epiphysiodesis (e.g., 27730 distal tibia, 27734 combined) is planned in a subsequent encounter, use modifier 58. Billing 27732 with 27734 on the same date is redundant — 27734 is the combined distal tibia and fibula code and would be the correct choice when both sites are addressed simultaneously.

Site-of-service matters here: HOPD and ASC payments differ significantly (see the Site of Service comparison table). Because this procedure is performed almost exclusively in pediatric or orthopedic subspecialty settings, payer prior-authorization requirements — particularly for commercial plans covering pediatric patients — are common. Confirm medical necessity documentation addresses skeletal age, predicted leg-length discrepancy, and timing of intervention before submitting.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	5.32
Practice expense RVU	6.77
Malpractice RVU	1.14
Total RVU	13.23
Medicare national rate	$441.89
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	$441.89
HOPD (APC 5113) Hospital outpatient department	$3,342.87
ASC (PI A2) Ambulatory surgical center (freestanding)	$1,644.87

Common denial reasons

The recurring reasons claims for CPT 27732 get rejected.

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

Missing or insufficient bone age documentation — payers require radiographic skeletal age, not just patient date of birth
Incorrect code selection when distal tibia was also arrested at the same session — 27734 should be billed instead of 27732 alone
Lack of prior authorization for elective growth-modulation surgery, especially under commercial pediatric plans
Absent predicted leg-length discrepancy calculation, leaving medical necessity unsupported in the record
Modifier 50 billed without payer-specific bilateral billing instructions confirmed — some payers require two line items with LT/RT instead

Frequently asked questions

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

01When should I bill 27732 versus 27734?

Bill 27734 when both the distal tibia and distal fibula are arrested at the same operative session — it's the combined code. 27732 is correct only when the distal fibula is arrested in isolation. Billing both 27732 and 27734 on the same date for the same leg is incorrect.

02Can 27732 be billed bilaterally?

Yes, if epiphysiodesis is performed on the distal fibula of both legs in the same session. Append modifier 50, or use LT and RT on separate lines depending on your payer's billing instructions. Confirm before submitting — payer rules on bilateral orthopedic surgery billing vary.

03Is this code used for physeal fracture repair?

No. 27732 is an elective growth-arrest procedure, not fracture care. Physeal fractures of the distal fibula are reported with fracture care codes. Conflating the two is a common audit flag.

04What modifiers apply when a planned contralateral epiphysiodesis is done at a later session?

Use modifier 58 — staged or related procedure during the global period. The staged nature should be documented in the original operative note or the pre-op plan for the second session.

05Does the 90-day global include follow-up limb-length X-rays?

The global covers routine post-op E&M visits, but the professional component of separately ordered imaging is generally billable outside the global. Confirm with your MAC — some global period guidance distinguishes between E&M and diagnostic radiology services.

06What documentation best supports medical necessity when a payer audits this code?

A bone age radiograph with a radiologist read, a documented leg-length discrepancy prediction using a recognized method (Moseley, multiplier), and an operative note that names the distal fibular physis as the target site. Vague indications like 'growth problem' without quantified discrepancy are the most common audit failure point.

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 laterality, the open approach, physeal identification, and the surgeon's stated indication (growth arrest for limb-length discrepancy versus angular deformity correction) directly from dictation. It flags if bone age and leg-length discrepancy prediction are referenced in the note — the two elements most commonly missing when payers audit 27732 for medical necessity.

See how Mira captures CPT 27732 documentation