Surgical · Wrist

Surgical reinforcement of the ulna using internal fixation devices such as nails, pins, plates, or wires — with or without methylmethacrylate — to prevent pathologic fracture before it occurs.

Verified May 8, 2026 · 6 sources ↓

Medicare: $694.74
Total RVUs: 20.8
Global, days: 90
Region: Wrist

Drawn from CMS

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Specify the fixation method by name — nail, pin, plate, or wire — and whether methylmethacrylate was used
Document the pathology driving the prophylactic indication: lesion type, location, cortical involvement, and fracture risk assessment
Record laterality explicitly (left, right, or bilateral) in both the operative note and the claim
Include imaging findings (X-ray, CT, or MRI) that support imminent fracture risk and justify prophylactic rather than therapeutic intervention
Note graft material or bone substitute if used, as this affects coding of ancillary procedures
Document that the procedure was performed before fracture occurred, not as a repair of an acute or pathologic fracture

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 50 Bilateral procedure 51 Multiple procedures 52 Reduced services 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 6 cited references ↓

CPT 25491 covers prophylactic fixation of the ulna, typically performed when a lesion, tumor, or structural compromise puts the bone at imminent risk of fracture. The surgeon reinforces the ulna with internal hardware — nailing, pinning, plating, or wiring — and may use methylmethacrylate cement as an adjunct. The goal is fracture prevention, not fracture treatment, which distinguishes this code from ulnar fracture repair codes in the 25500s range.

The 90-day global period means the operative visit, the procedure itself, and all routine post-op care through day 90 are bundled. Separate E/M visits within that window require modifier 24 (unrelated) or 25 (significant, separately identifiable). If the contralateral ulna is addressed at the same encounter, modifier 50 applies. If only a portion of the planned procedure is completed, modifier 52 is appropriate.

Code 25491 sits alongside 25490 (radius only) and 25492 (radius and ulna combined). Billing 25491 and 25490 together for the same arm on the same date will draw NCCI scrutiny — use 25492 when both bones are reinforced simultaneously. Document the specific fixation method used and the clinical rationale for prophylactic intervention; payers routinely request medical necessity support for preventive bone procedures.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	9.9
Practice expense RVU	8.79
Malpractice RVU	2.11
Total RVU	20.8
Medicare national rate	$694.74
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	$694.74
HOPD (APC 5115) Hospital outpatient department	$13,116.76
ASC (PI J8) Ambulatory surgical center (freestanding)	$8,621.29

Common denial reasons

The recurring reasons claims for CPT 25491 get rejected.

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

Lack of medical necessity documentation — payers require evidence of imminent fracture risk, not just a lesion diagnosis
Incorrect code selection when both radius and ulna are treated; 25492 should be billed instead of 25491 plus 25490
Missing laterality modifier when the payer requires LT or RT for forearm procedures
Post-op E/M visits billed without modifier 24 or 25 during the 90-day global period
Operative note describes a fracture repair workflow rather than prophylactic reinforcement, triggering a code audit against 25500-series codes

Frequently asked questions

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

01What separates 25491 from 25492?

25491 covers the ulna alone. 25492 covers prophylactic fixation of both the radius and ulna at the same encounter. Do not bill 25491 and 25490 together for the same arm on the same date — use 25492 instead.

02Can I bill 25491 after a pathologic fracture has already occurred?

No. 25491 is a prophylactic code — the procedure must occur before fracture. Once the bone has fractured, use the appropriate fracture treatment code from the 25500 series. Billing 25491 post-fracture misrepresents the encounter and will not survive a payer audit.

03Which modifier do I use if the procedure was performed on both ulnas at the same session?

Use modifier 50 for bilateral procedures. Some payers prefer separate line items with LT and RT instead — verify your payer's billing policy before submitting.

04Does the 90-day global period affect how I bill post-op oncology follow-up visits?

Yes. Routine post-op visits are bundled through day 90. If the follow-up is for a new or unrelated problem — such as ongoing oncology management unrelated to the surgery site — append modifier 24 to the E/M code and document the distinct medical necessity.

05Is fluoroscopy separately billable with 25491?

Generally no. Intraoperative fluoroscopic guidance used to confirm hardware placement is integral to the procedure under NCCI policy. Review your specific payer policy, but CMS does not allow separate reporting of CPT 76000 when it is routine to the surgical approach.

06What ICD-10 diagnosis codes support medical necessity for 25491?

Codes pointing to bone lesions with impending fracture risk are the standard justification — metastatic disease to bone, primary bone tumors, and benign lesions with significant cortical destruction. The ICD-10 code alone is insufficient; the operative note must describe measurable structural compromise and fracture risk.

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 fixation method (nail, pin, plate, or wire), use of methylmethacrylate, laterality, the underlying pathology, and the surgeon's fracture risk rationale from dictation. That prevents the most common denial trigger for 25491: an operative note that documents hardware placement but omits why prophylactic fixation was chosen over observation — leaving the payer unable to confirm medical necessity.

See how Mira captures CPT 25491 documentation