Open surgical procedure to arrest or correct growth of the lower leg epiphyses (tibia and/or fibula) — typically performed in skeletally immature patients to address limb length discrepancy.

Verified May 8, 2026 · 6 sources ↓

Medicare: $622.26
Work RVU: 8.61
Global, days: 90
Region: Foot & ankle

Drawn from CMSAAPCAcgmeEmednyThealliance

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 imaging (left hand/wrist radiograph), not just chronological age
Quantified limb length discrepancy with measurement method specified (scanogram, CT scout, clinical)
Remaining growth prediction documented — anticipated growth arrest timing based on bone age and standard growth charts
Operative note specifying which bone(s) treated (tibia, fibula, or both) and technique used (stapling, screw, or ablation)
Medical necessity narrative explaining why epiphysiodesis was chosen over alternative treatments
Pre-authorization obtained and referenced in the medical record where required by payer

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 51 Multiple procedures 52 Reduced services 58 Staged or related 59 Distinct service 62 Co-surgeons LT Left side RT Right side 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon AS PA/NP/CNS assistant

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 27734 describes an open epiphysiodesis or epiphyseal repair of the lower leg bones — the tibia, fibula, or both — performed to halt or correct abnormal growth at the growth plate. The procedure is performed in pediatric and adolescent patients who still have open physes, and the goal is typically to equalize limb length by slowing or stopping growth on the longer side. Surgical technique involves direct exposure and mechanical disruption or stapling of the physis. This is distinct from percutaneous or minimally invasive physis stapling, which would be coded differently.

The 90-day global period means that all routine postoperative visits, wound checks, staple or suture removal, and cast management through day 90 are bundled into the surgical fee. Anything unrelated to the epiphysiodesis billed during that window requires modifier 24 (E/M) or 79 (unrelated procedure). Modifier 58 applies if a staged procedure in the same region was planned and documented as such before the initial surgery.

This code appears in ACGME pediatric orthopaedic fellowship case log guidelines as a tracked procedure, reflecting its exclusive pediatric-focused application. Prior authorization is required by many payers — including Medicaid managed care plans — and must document skeletal age (bone age imaging), limb length discrepancy measurements, and expected remaining growth. Missing pre-auth or inadequate documentation of growth-plate status are the leading causes of denial.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU vs. total RVU

The work RVU (8.61) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (18.63) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	8.61
Practice expense RVU	8.19
Malpractice RVU	1.83
Total RVU	18.63
Medicare national rate	$622.26
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	$622.26
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 27734 get rejected.

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

Lack of prior authorization — most Medicaid managed care and commercial plans require pre-auth for this procedure
Insufficient documentation of limb length discrepancy magnitude or skeletal maturity to support medical necessity
Operative note too vague — failing to specify which bones were addressed or the surgical technique performed
Procedure billed with an adult patient whose growth plates are closed, triggering age-related medical necessity edits
Post-op E/M visits billed without modifier 24 during the 90-day global period, resulting in automatic bundling denials

Frequently asked questions

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

01Does 27734 cover both tibia and fibula if both are treated in the same operative session?

The code describes lower leg epiphyses broadly. If both tibia and fibula are addressed through the same incision, that is generally captured under a single unit of 27734. If separate incisions are used and distinct work is performed on each bone, modifier 22 with supporting documentation of increased complexity is appropriate — but don't bill two units without confirming payer policy, as MUE limits apply.

02Can 27734 be billed bilaterally?

Yes, if epiphysiodesis is performed on both legs in the same session, bill with modifier 50 (bilateral) or as two line items with LT and RT modifiers, depending on payer preference. Document the bilateral medical necessity explicitly — bilateral procedures are a known audit target for this code.

03What modifier applies if the patient returns within 90 days for a planned contralateral epiphysiodesis?

Use modifier 58 — staged or related procedure by the same physician during the global period. The staged nature must have been documented in the original operative plan. If it was unplanned and unrelated to the original procedure, modifier 79 applies instead.

04Is prior authorization typically required for 27734?

Yes, most commercial payers and Medicaid managed care plans (including California Alliance for Health and New York Medicaid) require prior authorization. The TAR or pre-auth request should include bone age imaging, quantified limb length discrepancy, and growth prediction data. Submitting without pre-auth is the most preventable denial for this code.

05How does the 90-day global period affect post-op management billing?

Routine post-op visits, wound care, and hardware monitoring through day 90 are bundled and cannot be billed separately. Use modifier 24 on E/M visits for unrelated problems (e.g., a new fracture visit or sick visit) and modifier 79 for unrelated surgical procedures. Hardware removal related to the epiphysiodesis within the global period requires modifier 78 if unplanned.

06What ICD-10 diagnosis codes are typically paired with 27734?

The most common pairing is M21.00–M21.069 (valgus/varus deformity) or Q68–Q74 series (congenital limb deformities) and M89.16x (physeal arrest). Limb length discrepancy is captured under M21.70–M21.779. Using an unspecified or adult-onset diagnosis code will trigger medical necessity edits given the pediatric nature of this procedure.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

Mira Scribe

Mira's AI scribe captures the operative dictation elements critical for 27734: which bone(s) were treated (tibia, fibula, or bilateral), the technique used (staple, screw, or direct ablation), confirmed open physis status, and the pre-op limb length discrepancy measurement. That specificity prevents the most common denial trigger — a vague operative note that fails to establish medical necessity or distinguish the open approach from less intensive alternatives.

See how Mira captures CPT 27734 documentation