Surgical repair of congenital pseudarthrosis of the tibia — a false joint formed at a congenital bowing site that failed to ossify normally.

Verified May 8, 2026 · 7 sources ↓

Medicare: $957.94
Total RVUs: 28.68
Global, days: 90
Region: Foot & ankle

Drawn from CMSAAOSAAPCFindacode

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Confirm diagnosis of congenital pseudarthrosis of the tibia, including prior imaging demonstrating congenital bowing and failed ossification
Document the specific surgical technique — resection margins, type of fixation (e.g., intramedullary rod), and graft source (autograft including harvest site, or allograft)
Record intraoperative fluoroscopy use; do not bill separately — it is integral to the procedure under NCCI policy
Document laterality (left or right tibia) explicitly in both the operative note and on the claim
Include pre-operative diagnosis, relevant prior treatments or failed conservative management, and clinical indication for surgical intervention
Note any concomitant procedures performed and their distinct indications if billing additional codes same-day

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 59 Distinct service 78 Unplanned return — related 79 Unrelated during global LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 27727 covers open surgical repair of congenital pseudarthrosis of the tibia. This is a rare but complex pediatric condition where a pathologic bow leads to fracture and failure of bony union, forming a false joint. The surgery typically involves resection of the pseudarthrosis site, bone grafting, and stabilization — often with intramedullary fixation — to achieve union and restore tibial alignment and function.

The 90-day global period applies. All routine post-op visits, wound checks, and cast or splint management through day 90 are bundled. Casting and strapping codes are not separately reportable when applied as part of the fracture/repair procedure — NCCI policy bundles them. If a genuinely unrelated procedure is performed during the global, append modifier 79. If a related return to the OR is required during the global, use modifier 78.

Site of service matters. HOPD and ASC payments differ substantially — see the Site of Service comparison table. The AAOS crosswalk maps 27727 to APC 5114 in the hospital outpatient setting. Document the specific stabilization technique, graft source (autograft vs. allograft), and intraoperative fluoroscopy use; fluoroscopy performed as an adjunct to the primary procedure is integral and not separately billable.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	14.47
Practice expense RVU	11.15
Malpractice RVU	3.06
Total RVU	28.68
Medicare national rate	$957.94
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	$957.94
HOPD (APC 5113) Hospital outpatient department	$3,342.87
ASC (PI G2) Ambulatory surgical center (freestanding)	$1,644.87

Common denial reasons

The recurring reasons claims for CPT 27727 get rejected.

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

Missing or non-specific diagnosis code — payers require an ICD-10 that maps to congenital pseudarthrosis of the tibia, not a generic fracture or nonunion code
Separate billing of casting, splinting, or fluoroscopy that is bundled into 27727 under NCCI policy
Laterality not specified on the claim — omitting LT or RT modifier triggers edits from many payers
Medical necessity not established — operative note lacks documentation of failed prior management or imaging-confirmed pseudarthrosis
Global period billing conflict — post-op E/M visits billed without modifier 24 within the 90-day global window

Frequently asked questions

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

01Is casting reportable separately when applied at the end of a 27727 procedure?

No. NCCI policy bundles casting, splinting, and strapping into fracture and reconstruction repair codes. Do not bill a cast or strapping code alongside 27727.

02What ICD-10 code supports 27727?

The primary diagnosis should reflect congenital pseudarthrosis — typically Q74.2 (other congenital malformations of lower limb) or M84.561/M84.562 for pathologic fracture in the context of the underlying condition. Confirm with your payer's accepted crosswalk; a generic tibia fracture code without congenital context is a common denial trigger.

03Can 27727 be billed with bone grafting codes?

Only if the graft procedure is performed at a separate anatomic site and constitutes a distinct service. If obtaining an autograft is included in the operative work described, it is bundled. Check current NCCI PTP edits before appending modifier 59 or XS.

04Does the 90-day global cover the initial post-op cast changes?

Yes. Routine cast changes, wound checks, and dressing changes within the 90-day global are included. Bill post-op E/M visits related to the surgery only if a significant, separately identifiable unrelated service is documented — and append modifier 24.

05When is modifier 22 appropriate for 27727?

Use modifier 22 when the procedure required substantially more work than usual — for example, a severely comminuted pseudarthrosis site, multiple prior failed repairs, or exceptionally complex fixation. The operative note must quantify the added complexity; a boilerplate claim without supporting documentation will not hold up on audit.

06Is 27727 appropriate for traumatic tibial nonunion?

No. Congenital pseudarthrosis of the tibia is a specific pathology. Traumatic nonunion repairs use different codes (e.g., 27722, 27724, 27725). Miscoding a traumatic nonunion as 27727 creates a diagnosis-to-procedure mismatch and a likely denial.

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 pseudarthrosis site location, resection technique, fixation method (including implant type and size), graft source with harvest site if autograft, and fluoroscopy use from surgeon dictation. This prevents the two most common audit flags for 27727: missing laterality and separately billed intraoperative imaging that NCCI bundles into the primary procedure.

See how Mira captures CPT 27727 documentation