Tibial nonunion or malunion repair by tibiofibular synostosis — surgically fusing the tibia to the fibula to restore structural integrity when the tibia has failed to heal or has healed in poor alignment.

Verified May 8, 2026 · 7 sources ↓

Medicare: $1,123.61
Total RVUs: 33.64
Global, days: 90
Region: Foot & ankle

Drawn from CMSAAPCEmedny

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Operative note must explicitly name synostosis technique and confirm tibiofibular fusion as the method — not just autograft harvest or internal fixation alone.
Imaging (X-ray or CT) documenting the nonunion or malunion prior to surgery, with radiologist or surgeon interpretation on record.
Narrative explanation of why prior healing failed or alignment was unacceptable, supporting medical necessity for synostosis rather than repeat standard fixation.
Intraoperative description of how tibia-fibula contact was achieved (bone decortication, hardware used, graft material if supplemented), including any method-specific details.
Postoperative plan with weight-bearing restrictions documented, establishing the clinical context for the 90-day global period management.
If bone graft was obtained separately, document the harvest site and method — do not bundle a separately coded graft harvest without confirming NCCI edit status.

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 57 Decision for surgery 58 Staged or related 59 Distinct service 62 Co-surgeons 76 Repeat, same physician 77 Repeat, another physician 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 27725 covers repair of a tibial nonunion or malunion by creating a synostosis between the tibia and fibula — any method. The fibula is used as a biological strut: bone contact is established between the two bones so the fibula shares load-bearing with the compromised tibia. This is not a standard fracture fixation code; it applies when prior healing has failed or the alignment is unacceptable and the surgical solution involves tibiofibular fusion rather than grafting alone.

This code carries a 90-day global period. All routine postoperative visits, wound checks, and hardware management related to the repair through day 90 are bundled. Unrelated procedures or E&M services during the global window require modifier 79 or 24, respectively. CMS has designated 27725 status indicator J1 under HOPD payment, meaning it maps to APC 05114 and is paid as a comprehensive APC — packaged services are not separately reimbursed.

27725 is also listed as a CMS inpatient-only (status C) procedure in historical Addendum E, though the 2026 OPPS data shows active status indicator J1 for outpatient. Confirm current inpatient-only status against the live 2026 OPPS Addendum B before billing in an outpatient hospital setting. The closely related codes 27720 (repair without graft), 27722 (sliding graft), and 27724 (iliac or other autograft) describe different repair methods; the distinction hinges on whether synostosis with the fibula is the technique performed.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	16.97
Practice expense RVU	13.06
Malpractice RVU	3.61
Total RVU	33.64
Medicare national rate	$1,123.61
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	$1,123.61
HOPD (APC 5114) Hospital outpatient department	$7,413.38
ASC (PI J8) Ambulatory surgical center (freestanding)	$4,801.02

Common denial reasons

The recurring reasons claims for CPT 27725 get rejected.

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

Inpatient-only designation conflict: historically listed as status C; billing at an outpatient facility without verifying current 2026 OPPS status triggers an automatic denial.
Operative note describes autograft technique only, causing payer to re-route the claim to 27724 (with iliac/autograft) rather than 27725 (synostosis with fibula).
Missing pre-operative imaging or inadequate documentation of nonunion/malunion diagnosis, failing to establish medical necessity for the synostosis approach.
Global period billing conflict when post-op E&M or related procedures are billed without the correct modifier (24, 78, or 79) during the 90-day window.
Incorrect laterality documentation when bilateral tibial pathology exists — absence of LT/RT modifiers causes claim routing errors or duplicate-service edits.

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 7 cited references ↓

01What is the difference between CPT 27725 and 27724?

27724 covers tibial nonunion/malunion repair using an iliac or other autograft. 27725 is specifically for repair by tibiofibular synostosis — any method. If the operative technique involved fusing the tibia to the fibula as the primary repair strategy, 27725 is correct. If the repair relied on an autogenous bone graft without creating tibiofibular synostosis, use 27724.

02Is CPT 27725 inpatient-only?

It was designated inpatient-only (status C) in historical CMS OPPS Addendum E, but the 2026 OPPS data assigns it status indicator J1 under APC 05114. Always verify against the current year's live Addendum B before billing outpatient — payer policy and annual OPPS updates can change this designation.

03What global period applies, and what's included?

27725 carries a 90-day global period. The day-before pre-op visit, the procedure itself, and all routine post-op care through day 90 are bundled. Any E&M service unrelated to the repair during that window requires modifier 24. A related return to the OR requires modifier 78. An unrelated procedure in the global period requires modifier 79.

04Can you bill bone graft harvest separately with 27725?

Only if the graft harvest is performed through a separate incision and is not already integral to the synostosis technique described. Check current NCCI PTP edits for the specific graft harvest code pairing before reporting separately — use modifier 59 or XS only when the edit allows it and the documentation supports a distinct service.

05If the surgery is done on both tibiae, how is billing handled?

Bilateral tibial synostosis on the same day is uncommon but would require modifier 50, with LT and RT laterality appended as needed. Document each side independently in the operative note. Payer policies on bilateral reimbursement rates vary — some pay 150% of the single-procedure rate, others apply a different reduction factor.

06What ICD-10 diagnoses support medical necessity for 27725?

Tibial nonunion (M84.361–M84.369 by laterality) and tibial malunion (M84.361-series with malunion specificity) are the primary supporting diagnoses. Post-traumatic codes from prior fracture sequelae may also apply depending on the clinical history. Confirm that imaging findings documented in the chart match the diagnosis code submitted.

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 synostosis technique by name from dictation — confirming tibiofibular contact method, hardware placed, and any supplemental graft material — along with the nonunion or malunion diagnosis supported by pre-op imaging findings. This prevents downcoding to 27720 or 27724 when the operative note is ambiguous about whether fibular synostosis was actually the repair strategy used.

See how Mira captures CPT 27725 documentation