Joint replacement · Hip

27156

Osteotomy of the iliac, acetabular, or innominate bone with concurrent femoral osteotomy and reduction of hip dislocation

Verified May 8, 2026 · 6 sources ↓

Medicare
$1,533.44
Total RVUs
45.91
Global, days
90
Region
Hip
Drawn from CMSAAOS

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

  • Specify each osteotomy performed by name — iliac, acetabular, innominate, and/or femoral — and document that all components were completed
  • Operative note must describe the degree of correction achieved and confirm hip reduction was performed
  • Preoperative imaging (AP pelvis, frog-leg lateral) documenting structural hip dysplasia or dislocation requiring surgical correction
  • Failed or inadequate conservative treatment history establishing medical necessity for bilateral or unilateral surgical intervention
  • Document the surgical approach by name (e.g., Smith-Petersen, Watson-Jones) — notes that reference only 'standard approach' flag in audit
  • If modifier 22 is appended, the operative note must quantify the additional work and explain why complexity exceeded typical — surgeon attestation alone is insufficient

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 6 cited references ↓

CPT 27156 describes a combined pelvic and femoral osteotomy procedure performed to correct hip dysplasia or structural malalignment. The surgeon cuts the iliac, acetabular, or innominate bone to reorient the acetabular socket, then performs a separate femoral osteotomy to correct the proximal femur alignment, and reduces the dislocated hip. This is a high-complexity reconstructive procedure, not a simple revision — the dual osteotomy component drives its substantial RVU weight.

The 90-day global period covers the surgery date, the day-before decision visit (modifier 57 required on the E/M), and all routine postoperative care through day 90. Separate billing for cast changes, dressing care, or routine follow-up visits during the global window will deny without modifiers 24 or 79 paired with a distinct, unrelated diagnosis.

Site of service matters significantly for this code. HOPD and ASC facility payments differ — see the site-of-service comparison table on this page. Most payers, including Medicare, require prior authorization for elective hip reconstructive procedures of this magnitude. Confirm coverage criteria and document medical necessity with imaging, failed conservative treatment history, and functional status 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 RVU25.57
Practice expense RVU14.89
Malpractice RVU5.45
Total RVU45.91
Medicare national rate$1,533.44
Global period90 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
$1,533.44
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 27156 get rejected.

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

  • Missing prior authorization — most commercial payers and Medicare Advantage plans require it for elective pelvic/femoral reconstructive procedures
  • Operative note documents only one osteotomy (pelvic or femoral) rather than the combined procedure required for 27156
  • Medical necessity not established — absence of imaging or documented failed conservative management in the record
  • Bundling conflict when additional musculoskeletal codes are billed same-day without a modifier establishing distinct procedural independence
  • Global period violation — routine post-op visits billed without modifier 24 or 79 during the 90-day window

Frequently asked questions

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

01What distinguishes 27156 from other hip osteotomy codes like 27146 or 27151?
27156 requires both a pelvic osteotomy (iliac, acetabular, or innominate) AND a femoral osteotomy performed together with hip reduction. 27146 covers pelvic osteotomy alone, and 27151 covers femoral osteotomy alone. Bill 27156 only when both components plus reduction are performed in the same operative session.
02Can 27156 be billed bilaterally in the same session?
Bilateral same-session procedures require modifier 50. Document each side's osteotomy and reduction independently in the operative note. Some payers require separate line items with LT and RT instead of a single line with modifier 50 — verify your payer's bilateral billing policy before submitting.
03Does modifier 57 apply to the decision visit for 27156?
Yes. Because 27156 carries a 90-day global period, any E/M visit at which the decision for this surgery is made requires modifier 57. This applies whether the decision visit occurs the day before or the day of surgery. Without modifier 57, the E/M will be denied as included in the global.
04What ICD-10 diagnoses support medical necessity for 27156?
Developmental dysplasia of the hip (Q65.xx series), congenital hip dislocation, and acquired hip instability or subluxation codes are the primary supporting diagnoses. The ICD-10 code must match the documented structural pathology — a mismatch between a dislocation diagnosis and an operative note describing only alignment correction is a common cause of payer audit.
05If a complication requires return to the OR within the 90-day global, what modifier applies?
Modifier 78 applies if the return procedure is related to the original surgery (e.g., wound dehiscence, hardware failure at the osteotomy site). Modifier 79 applies if the return procedure is unrelated to 27156. Do not use 78 for unrelated procedures — that inversion is an audit trigger.
06Is 27156 performed in an ASC setting, or does it require inpatient?
27156 has both HOPD and ASC payment rates under CMS (see the site-of-service comparison table on this page), so outpatient facility billing is supported. However, the clinical complexity — combined pelvic and femoral osteotomy with hip reduction — typically results in inpatient admission. Confirm the patient's site of service status and use the correct place of service code, as it directly affects the physician's payment rate.

Mira AI Scribe

Mira's AI scribe captures the specific bones osteotomized (iliac, acetabular, innominate, femoral), the degree of correction, confirmation of hip reduction, surgical approach by name, and intraoperative findings from dictation. That structured capture prevents the most common audit flag for 27156 — operative notes that describe only one osteotomy component, which misrepresents the procedure and triggers downcoding or denial.

See how Mira captures CPT 27156 documentation

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