Surgical · Hip

Surgical arrest of greater trochanter growth by epiphysiodesis or stapling of the proximal femoral epiphysis.

Verified May 8, 2026 · 5 sources ↓

Medicare: $677.04
Total RVUs: 20.27
Global, days: 90
Region: Hip

Drawn from CMSAAPCFastRVU CPTFindACode CPT

Documentation requirements

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

Source · Editorial brief grounded in 5 cited references ↓

Preoperative imaging (AP pelvis and femur X-rays or MRI) demonstrating open growth plate and clinical indication such as coxa valga or trochanteric overgrowth
Skeletal maturity assessment or bone age determination supporting the decision to perform growth arrest at this stage
Operative note specifying technique — epiphysiodesis versus staple/screw implantation — and hardware type, size, and number placed
Explicit laterality documentation (left, right, or bilateral) in both the operative note and the procedure order
Clinical rationale linking the identified deformity or discrepancy to the selected surgical approach and expected correction
Post-operative plan for serial radiographic monitoring to assess growth plate response and hardware position

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 52 Reduced services 58 Staged or related 59 Distinct service LT Left side RT Right side 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon

What this code covers

Source · Editorial summary grounded in 5 cited references ↓

CPT 27185 covers open surgical arrest of the greater trochanter epiphysis, accomplished by epiphysiodesis or implantation of screws or staples into the growth plate. The goal is to slow or halt trochanteric overgrowth — most commonly used in pediatric patients with coxa valga, limb length discrepancy, or post-Perthes deformity where unchecked trochanteric growth would degrade hip biomechanics and abductor lever-arm function.

This is an inpatient-only procedure under CMS. Medicare classifies 27185 as a status indicator 'C' code under the Hospital Outpatient Prospective Payment System, meaning it cannot be billed in an HOPD or ASC setting for Medicare beneficiaries — it must be performed in an inpatient hospital. The 90-day global period applies, covering all routine post-op care through day 90, including follow-up imaging appointments to assess growth arrest progress.

Given the pediatric population this code predominantly serves, payer mix matters: Medicaid managed care plans and commercial pediatric policies may carry prior authorization requirements and medical necessity criteria that differ substantially from Medicare. Document the skeletal maturity assessment, the clinical indication (e.g., trochanteric overgrowth ratio on AP pelvis radiograph), and the specific hardware used. Operative notes that omit laterality or fail to name the technique — epiphysiodesis versus stapling — are the most common audit triggers.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	9.55
Practice expense RVU	8.68
Malpractice RVU	2.04
Total RVU	20.27
Medicare national rate	$677.04
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	$677.04
HOPD (APC 5113) Hospital outpatient department	$3,342.87
ASC (PI J8) Ambulatory surgical center (freestanding)	$2,084.06

Common denial reasons

The recurring reasons claims for CPT 27185 get rejected.

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

Procedure billed in outpatient or ASC setting for Medicare — 27185 is inpatient-only (CMS status indicator C) and will be denied if submitted on an outpatient claim
Missing or insufficient medical necessity documentation — payers require imaging evidence of trochanteric overgrowth or coxa valga with clinical correlation, not just a diagnosis code
Laterality not specified in the operative note, triggering a coding mismatch between the claim and supporting documentation
Prior authorization not obtained for commercial or Medicaid managed care plans, which frequently require it for pediatric growth plate procedures
Operative note describes only 'standard approach' or 'routine epiphysiodesis' without naming the technique or hardware, flagging the note as insufficient for audit review

Frequently asked questions

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

01Can 27185 be performed in an ASC or hospital outpatient setting for Medicare patients?

No. CMS designates 27185 as an inpatient-only procedure (status indicator C under HOPPS). Billing it on an outpatient or ASC claim for a Medicare beneficiary will result in denial. It must be performed and billed as an inpatient hospital stay.

02What modifier applies if 27185 is performed bilaterally in the same session?

Append modifier 50 for a bilateral procedure and bill on a single line, or bill two lines with LT and RT per payer preference. Confirm the payer's preferred bilateral billing format before submitting — Medicare and many commercial plans differ on this.

03What is the global period for 27185, and what does it cover?

27185 carries a 90-day global period. It covers the day before surgery, the procedure day, and all routine post-op visits through day 90 — including follow-up X-rays performed as part of standard post-operative monitoring. Bill modifier 24 for unrelated E/M visits or modifier 79 for unrelated procedures performed during the global window.

04Which ICD-10 diagnosis codes are typically paired with 27185?

Common pairings include Q65.81 (congenital coxa valga), M91-range codes for juvenile osteochondrosis of the hip, and appropriate sequelae codes following prior hip conditions such as Legg-Calvé-Perthes disease. The diagnosis must reflect the specific deformity or discrepancy documented in preoperative imaging.

05Is modifier 58 appropriate when 27185 follows a prior hip procedure during the global period of that earlier surgery?

Yes. If 27185 is planned or staged following a related prior procedure and is performed within that procedure's global period, modifier 58 (staged or related procedure by the same physician) is correct. Do not use modifier 78 — that is reserved for unplanned returns to the OR for a complication-related procedure.

06Does 27185 require prior authorization from commercial payers?

Most commercial and Medicaid managed care plans require prior authorization for inpatient pediatric orthopedic procedures, including growth plate arrests. Obtain auth before scheduling and confirm the specific ICD-10 and CPT codes are covered under the auth number. Retro-authorization approvals are payer-variable and often denied.

Sources & references

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

01CMS Physician Fee Schedule 2026
02CMS Inpatient-Only Procedure List (Status Indicator C) — https://www.cms.gov/medicare/medicare-fee-for-service-payment/hospitaloutpatientpps/downloads/cms-1427-p_adde.pdf
03AAPC Codify — CPT 27185 — https://www.aapc.com/codes/cpt-codes/27185
04FastRVU CPT 27185 — https://fastrvu.com/cpt/27185
05FindACode CPT 27185 — https://www.findacode.com/cpt/27185-cpt-code.html

Mira AI Scribe

Mira's AI scribe captures the surgical technique (epiphysiodesis versus staple/screw fixation), hardware description, laterality, the clinical indication tied to imaging findings (e.g., trochanteric overgrowth ratio, coxa valga angle), and the skeletal maturity assessment from the surgeon's dictation. This prevents the most common audit flag on 27185: an operative note that names the diagnosis but omits technique specifics and the imaging rationale that justifies growth arrest timing.

See how Mira captures CPT 27185 documentation