Surgical · Knee

27475

Surgical arrest of distal femoral growth plate (epiphysiodesis) to equalize limb length discrepancy

Verified May 8, 2026 · 5 sources ↓

Medicare
$627.27
Work RVU
8.71
Global, days
90
Region
Knee
Drawn from CMSAAPCMdclarityEmedny

Documentation requirements

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

Source · Editorial brief grounded in 5 cited references ↓

  • Pre-operative standing full-length radiographs documenting measured limb length discrepancy in centimeters
  • Skeletal age assessment (bone age study) confirming sufficient remaining growth to achieve equalization
  • Operative note naming the specific technique used (open drilling/curettage vs. percutaneous screw epiphysiodesis)
  • Laterality explicitly documented — right, left, or bilateral — with each affected physis identified
  • Clinical indication linking the discrepancy to the diagnosis code (e.g., congenital, post-traumatic, post-infectious)
  • Surgeon attestation that the growth plate was targeted and the degree of physeal destruction achieved

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

What this code covers

Source · Editorial summary grounded in 5 cited references ↓

CPT 27475 describes surgical epiphysiodesis at the distal femur, where the surgeon partially or completely ablates the growth plate to halt longitudinal bone growth on the longer side, allowing the shorter limb to catch up. The procedure is performed in skeletally immature patients with documented limb length discrepancy and sufficient remaining growth potential to justify intervention. Techniques include open physeal curettage/drilling or percutaneous screw-based methods; the specific technique should be named in the operative note.

The code carries a 90-day global period. All routine post-op visits, wound checks, and stitch removals through day 90 are bundled. Unrelated problems treated in that window require modifier 24 on the E/M. If a complication sends the patient back to the OR for a related procedure, bill that return with modifier 78. An unrelated surgical problem addressed during the global period uses modifier 79.

Lateral and medial modifiers (LT/RT) apply when only one side is treated. If both distal femora are addressed in the same session, append modifier 50. When the procedure is performed bilaterally and also involves the proximal tibia (27477), each code is reported with the appropriate side modifier and modifier 51 for the secondary code.

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 (8.71) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (18.78) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU 8.71
Practice expense RVU 8.22
Malpractice RVU 1.85
Total RVU 18.78
Medicare national rate $627.27
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

SettingMedicare rate (national)
Office (PFS non-facility)
Procedure performed in physician's office
$627.27
HOPD (APC 5114)
Hospital outpatient department
$7,413.38
ASC (PI G2)
Ambulatory surgical center (freestanding)
$3,695.53

Common denial reasons

The recurring reasons claims for CPT 27475 get rejected.

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

  • Missing or insufficient bone age documentation to justify timing of physeal arrest
  • Laterality not specified in the operative note, triggering a missing-modifier edit
  • Procedure billed without prior authorization when payer requires PA for pediatric growth-arrest surgery
  • ICD-10 diagnosis code mismatch — using an adult limb-deformity code instead of a congenital or acquired discrepancy code appropriate for a skeletally immature patient
  • Global period conflict when a post-op visit is billed without modifier 24 for an unrelated condition within the 90-day window

Frequently asked questions

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

01When should I use modifier 50 vs. LT/RT on 27475?
Use LT or RT when only one distal femur is treated. Use modifier 50 when both distal femora are addressed in the same operative session. Don't stack 50 with LT or RT — pick one approach and be consistent with how your payer wants bilateral procedures listed (single-line with 50 vs. two lines with LT/RT).
02Can 27475 and 27477 be billed together?
Yes. If the surgeon performs epiphysiodesis at both the distal femur (27475) and proximal tibia/fibula (27477) in the same session, report both codes. Append modifier 51 to the lower-value code. Document each physis separately in the operative note — a single generic statement that 'growth plates were treated' won't support two codes under audit.
03What ICD-10 codes pair correctly with 27475?
The most common pairings are M21.76x (unequal limb length, femur — specify laterality), Q72.0–Q72.2 (congenital reduction defects), and M89.16x (physeal arrest, femur). Avoid adult deformity codes that imply skeletal maturity, which directly contradict the medical necessity basis of a growth-arrest procedure.
04Is fluoroscopic guidance separately billable with 27475?
Intraoperative fluoroscopy is generally considered integral to percutaneous epiphysiodesis techniques and is not separately reportable. For open techniques where a surgeon can make a credible argument that fluoroscopy was separately identifiable and provided distinct guidance, check payer policy — most commercial payers and Medicare bundle it.
05Does the 90-day global period create billing problems for the cast or brace checks afterward?
Routine post-op visits, gait assessments, and hardware checks within 90 days are bundled — bill nothing separately. If the patient presents with an unrelated problem (e.g., a new injury, unrelated illness), bill the E/M with modifier 24. A planned hardware removal of the epiphysiodesis screws within the global period uses modifier 58 if it was staged, or 78 if it was unplanned and related.
06When does modifier 22 apply to 27475?
Modifier 22 is warranted when the procedure required substantially more work than typical — for example, a severely obese pediatric patient requiring unusual positioning, or a prior surgical site with dense scarring that significantly complicated access to the physis. You need a cover letter quantifying the additional time and complexity, and documentation in the operative note must support it.

Mira Scribe

Mira's AI scribe captures the specific physis targeted (distal femur medial, lateral, or complete), surgical technique by name (percutaneous screw vs. open drill-and-curet), measured limb length discrepancy in centimeters, bone age at time of surgery, and laterality. This prevents the two most common denials on 27475: missing bone-age support for medical necessity and absent laterality that triggers a modifier edit at the payer.

See how Mira captures CPT 27475 documentation

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