Open surgical repair of a failed-to-heal carpal bone (excluding scaphoid), typically involving bone graft and internal fixation to achieve union.

Verified May 8, 2026 · 7 sources ↓

Medicare: $738.83
Total RVUs: 22.12
Global, days: 90
Region: Wrist

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Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Specify the exact carpal bone involved by name (e.g., lunate, capitate, hamate body — not just 'carpal bone') to confirm this is not a scaphoid nonunion.
Document radiographic or advanced imaging evidence (CT preferred) confirming nonunion, including duration since original injury or fracture.
Describe the nonunion site preparation, type of bone graft used (autograft, allograft, synthetic), and the donor site if autograft was harvested.
Detail fixation method by name (headless compression screw, K-wire, plate and screws) and implant size/count placed.
Note any neurovascular structures encountered or protected during the dissection, particularly the motor branch of the ulnar nerve if operating near the hook of hamate.
Confirm the wrist approached by side (LT/RT) with unambiguous laterality documentation in both the operative note and on the claim.

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 24 Unrelated E/M during global 25 Significant separate E/M 51 Multiple procedures 58 Staged or related 59 Distinct service 62 Co-surgeons 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon LT Left side RT Right side XS Separate structure

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 25431 covers open repair of a nonunion in any carpal bone except the scaphoid. The procedure addresses a wrist bone that has failed to heal despite initial fracture management, requiring the surgeon to debride the nonunion site, apply bone graft (autograft harvest is included — do not bill separately), and stabilize the construct with fixation hardware as needed. Scaphoid nonunion has its own dedicated code family; if that's the bone involved, 25431 is the wrong code.

This is a 90-day global procedure. All related post-op E/M visits, dressing changes, and routine cast or splint management through day 90 are bundled into the base payment. Bill modifier 24 for an unrelated E/M during the global, modifier 78 for an unplanned return to the OR for a related complication, and modifier 79 for an unrelated operative procedure in that window. Hardware removal (20670, 20680) is not separately billable if it's a necessary component of the same operative session.

NCCI bundles 10+ codes with 25431. Modifier indicator 1 edits can be bypassed with modifier 59 or an X-modifier when procedures are performed at distinctly separate anatomical sites with supporting documentation. Indicator 0 edits cannot be bypassed regardless of modifiers.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	10.62
Practice expense RVU	9.24
Malpractice RVU	2.26
Total RVU	22.12
Medicare national rate	$738.83
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	$738.83
HOPD (APC 5114) Hospital outpatient department	$7,413.38
ASC (PI J8) Ambulatory surgical center (freestanding)	$5,390.52

Common denial reasons

The recurring reasons claims for CPT 25431 get rejected.

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

Wrong code selected — scaphoid nonunion repairs have their own code series; 25431 on a scaphoid case triggers a coding mismatch denial.
Lack of medical necessity documentation — payer requires imaging proof of nonunion and evidence that conservative management failed before authorizing open repair.
Bone graft billed separately when it's already bundled into the 25431 reimbursement for autograft harvest.
Hardware removal billed separately (20670/20680) in the same operative session when it was an integral step of the nonunion repair, not a distinct service.
Missing or ambiguous laterality — claim submitted without LT or RT modifier leads to edit-level rejection at many MACs and commercial payers.
Post-op E/M visits billed without modifier 24 or 25 during the 90-day global period, flagged as duplicate payment for bundled post-op care.

Frequently asked questions

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

01Does 25431 cover scaphoid nonunion repair?

No. Scaphoid nonunion has its own dedicated CPT codes. Using 25431 for a scaphoid case will draw a coding mismatch denial. Reserve 25431 for all other carpal bones — lunate, capitate, hamate, trapezium, trapezoid, triquetrum, and pisiform.

02Is autograft harvest separately billable with 25431?

No. Graft procurement is included in the 25431 work value. Billing a separate graft harvest code on the same claim is an NCCI bundling violation.

03Can hardware removal be billed alongside 25431 in the same session?

Only if the removal is a distinct, separate procedure unrelated to the nonunion repair. If removing old hardware was a necessary step to access and repair the nonunion site, CPT 20670 and 20680 are not separately reportable per NCCI policy.

04What modifiers apply when billing 25431 during the global period of a prior wrist procedure?

Use modifier 78 if the return to the OR is for a complication related to the original procedure. Use modifier 79 if 25431 is being performed for a completely unrelated condition during an existing global period. Document clearly which scenario applies — payers audit both.

05Is prior authorization typically required for 25431?

Most commercial payers require it. You'll need imaging confirmation of nonunion (CT is standard), the original injury date, prior treatment history, and a statement of failed conservative management. Medicare does not require prior auth, but documentation of medical necessity must still support the claim.

06How should laterality be reported on the claim?

Always append LT or RT to the 25431 line. Omitting laterality is a common MAC edit trigger. For facility claims at ASCs, some payers require separate line items with LT and RT rather than modifier 50 — check your payer contract.

07Can modifier 22 be used with 25431 for increased procedural complexity?

Yes, when the nonunion repair involves documented extraordinary circumstances — severe bone loss, vascular pedicle grafting, or significant additional operative time beyond the standard procedure. Attach a cover letter to the claim explaining the increased complexity and include the operative report. Most payers will not pay modifier 22 without documentation.

Sources & references

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

Mira AI Scribe

The Mira AI Scribe captures the specific carpal bone name, imaging-confirmed nonunion diagnosis, graft source and type, fixation hardware details, and operative laterality directly from surgeon dictation. That structured capture prevents the two most common 25431 denials: miscoding a scaphoid case to this code and missing laterality on the claim.

See how Mira captures CPT 25431 documentation