CPT code 25118: Synovectomy, extensor tendon sheath, wrist

Key takeaways

CPT code 25118 describes synovectomy of the extensor tendon sheath at the wrist, single compartment.

Rheumatoid arthritis and tenosynovitis are the most common indications, supported by ICD-10 codes M05.831, M06.031, and M65.031.

CPT 25119 adds resection of the distal ulna, while radical multi-compartment disease maps to CPT 25115 or 25116.

CMS puts 25118 at 11.07 total RVUs for 2026 with a 90-day global period, so post-op visits inside that window need a modifier.

Pabau’s claims management software helps orthopedic and hand surgery practices track claim status, apply correct modifiers, and reduce denials.

CPT code 25118 covers synovectomy of the extensor tendon sheath at the wrist, single compartment. The surgeon strips inflamed synovial lining from one of the six dorsal wrist compartments. No bone is removed. That last point is what separates 25118 from CPT 25119.

Most denials on this code come from three places. Modifier selection is the first. Operative notes that never state the single-compartment scope are the second. The third is a post-op visit billed inside the 90-day global period. Purpose-built sports medicine practice software flags all three before the claim goes out.

The American Medical Association’s CPT code set places 25118 in the Musculoskeletal System section, under Excision Procedures on the Forearm and Wrist. The official descriptor reads: Synovectomy, extensor tendon sheath, wrist, single compartment. The aim is to relieve pain and restore wrist extension.

The single-compartment qualifier is what limits this code. Six extensor tendon compartments run across the dorsal wrist, each holding distinct tendons. CPT code 25118 covers only one of them. Radical tenosynovectomy across multiple sheaths is coded elsewhere, with CPT 25115 for flexor sheaths and CPT 25116 for extensor sheaths.

Clinical indications and when to use CPT 25118

Synovectomy of the extensor tendon sheath is performed when conservative management has failed to control synovial inflammation. That means corticosteroid injections, splinting, and physical therapy have not worked. The procedure is most common in patients whose inflammatory condition causes pain, swelling, or lost wrist extension.

Correct use of CPT code 25118 depends on confirming both the anatomical site and the scope. If the note does not establish extensor tendon sheath, wrist, and a single compartment, 25118 is the wrong code.

Hand therapists deliver much of the conservative care that comes first. Practices running that care on occupational therapy software should log every modality that failed. That log is what establishes medical necessity when a payer reviews the surgery.

• Rheumatoid arthritis (RA): The most common indication. Chronic synovial inflammation in RA patients can cause the extensor tendon sheath to thicken, restricting wrist movement.
• Tenosynovitis: Inflammatory tenosynovitis that does not respond to non-operative care. The disease must be localized to one compartment to match the descriptor.
• Seronegative inflammatory arthropathy: Conditions such as psoriatic arthritis or reactive arthritis producing localized extensor tenosynovitis.
• Pigmented villonodular tenosynovitis (PVNS): A benign but locally aggressive condition of the synovial tissue requiring surgical excision.

Payer LCD policies vary on coverage. Confirm pre-authorization for rheumatoid indications before scheduling. Some commercial plans require documented failure of at least two conservative treatment modalities.

ICD-10 codes linked to CPT code 25118

Medical necessity for CPT code 25118 must be supported by an appropriate ICD-10-CM diagnosis code. Laterality drives the choice. Codes ending in 1 indicate the right wrist, 2 the left wrist, and 3 both wrists. Use the most specific code available, or the claim will be denied on specificity grounds.

Hand and wrist tendon diagnoses follow the same laterality pattern, as S66.292D shows. The table below maps the diagnosis codes most often paired with this procedure.

Verify each code against current CMS ICD-10-CM guidelines before filing. Payer LCD and NCD policies vary, and a specific ICD-10 code does not guarantee coverage. Some commercial payers want 7th-character detail where the code family supports it, as S63.631D does.

Reimbursement rates and Medicare fee schedule for CPT code 25118

Medicare reimbursement for CPT code 25118 runs on the Resource-Based Relative Value Scale, or RBRVS. Total payment reflects three RVU components multiplied by the annual conversion factor. That result is then adjusted for location through the Geographic Practice Cost Index, known as GPCI.

Office and facility rates usually differ, because practice expense RVUs run higher in an office setting. CPT 25118 works differently. CMS marks its non-facility practice expense as not applicable, so the file carries one total for both settings.

Use the CMS Physician Fee Schedule lookup tool to pull locality-specific rates for the current year. The figures below come from the January 2026 national relative value file. Values are refreshed annually, so check the current release before billing.

RVU breakdown for CPT 25118

Those are national values, before any geographic adjustment. Multiply 11.07 by the 2026 conversion factor of $33.4009 and the allowable is about $370. Clinicians in a qualifying alternative payment model use a slightly higher factor of $33.5675.

Commercial rates are negotiated separately. Most land at a percentage of the Medicare allowable, so the RVU total still drives the number.

Applicable modifiers for CPT code 25118

Modifier selection directly affects claim adjudication for CPT code 25118. Missing or incorrect modifiers are among the top denial reasons for wrist surgery codes. Check the current NCCI edits before billing, because CMS updates them quarterly.

Global period and post-op billing rules for CPT code 25118

CPT code 25118 carries a 90-day global surgery period, consistent with major surgical procedures in the musculoskeletal system. During this window, routine post-operative services are bundled into the surgical payment and cannot be billed separately.

• Included in the global period: Pre-operative evaluation on the day of surgery, by the same physician, plus intraoperative and immediate post-operative care. Suture removal, routine wound checks, and related follow-up visits within 90 days are also bundled.
• Not included (may be billed separately with modifier -24): Evaluation and management visits for a condition unrelated to the surgery. This also covers a new problem that appears during the global period. Document the unrelated diagnosis clearly in the visit note.
• Modifier -79 for unrelated procedures: Append modifier -79 when a different surgical procedure is needed during the global period. It tells the payer the new procedure is unrelated.
• Modifier -78 for return to the OR: Use modifier -78 when the patient returns to the operating room during the global period. It applies to complications of the original procedure.

Billing a standard office visit during the 90-day global period without a modifier is one of the most common denials for this code. The same window governs other upper-limb procedures, including CPT 23650.

Train front desk and billing staff to flag every post-operative appointment for 25118 patients. The modifier decision happens before submission, not after the denial arrives.

CPT 25118 vs. CPT 25119: Key differences

The most frequent coding question around CPT code 25118 is how it differs from CPT 25119. Both describe the same single-compartment synovectomy of the extensor tendon sheath at the wrist. The difference is bone work.

CPT 25119 adds resection of the distal ulna, known as a Darrach-type resection. Nothing in 25119 signals a wider synovectomy. Coders who read it as the extensive version of 25118 pick the wrong code.

The operative report decides the code. If the surgeon cleaned out one extensor compartment and left the ulna alone, CPT code 25118 is correct. If the same operation included resection of the distal ulna, report CPT 25119 on its own. If the note describes radical tenosynovectomy across several sheaths, move to CPT 25115 or CPT 25116.

At the 2026 conversion factor, the two codes sit about $117 apart per case. That is what an ambiguous operative note costs when the coder has to guess. Picking the closer-looking code without documentation support is also a compliance risk.

Related CPT codes in the forearm and wrist section

Orthopedic and hand surgery billing teams meet CPT code 25118 alongside companion codes in the same anatomical grouping. Knowing the family prevents under-coding, over-coding, and bundling errors. The total RVU column below uses the January 2026 national file. Differences in surgical scope therefore show up as differences in payment.

Prophylactic treatment of the same bones sits further out in the family, at CPT 25492. It carries 25.25 total RVUs, more than twice this code. A desk-level coding cheat sheet helps when a note could plausibly land in more than one range.

Billing and documentation requirements for CPT code 25118

Documentation problems are the primary reason CPT code 25118 claims are denied on audit rather than at submission. The operative report has to support the code before the claim is filed.

Practices running claims management software can build pre-submission checklists that flag missing operative report elements. HIPAA compliance also requires that operative documentation stays secure and retrievable for a payer audit.

Operative report requirements

• Anatomical site: Explicitly name extensor tendon sheath and wrist. Generic wrist surgery language is not enough.
• Compartment count: State the specific compartment number, such as first extensor compartment. Alternatively, describe that only a single compartment was addressed. This is the documented basis for choosing 25118 over 25115 and 25116.
• Distal ulna: State whether the distal ulna was resected. That one detail separates CPT 25118 from CPT 25119, so an ambiguous note invites a downcode or an audit finding.
• Extent of synovial excision: Describe the tissue removed, not just the incision made. Note the degree of synovial hypertrophy found and the amount of tissue excised.
• Laterality: Right or left wrist, stated clearly in the operative header and in the body of the report.
• Clinical indication: Cite the diagnosis, such as rheumatoid tenosynovitis or PVNS. Note failure of conservative treatment where it applies.

Pre-authorization and common denial reasons

Many commercial payers require pre-authorization for CPT code 25118. Submit the request with the operative plan, the supporting ICD-10 code, and evidence of prior conservative treatment. A standard prior authorization form keeps those three elements in one place.

Medicare does not require pre-authorization for this code. Documentation still has to support medical necessity on any retrospective audit.

Four denials account for most of the recoverable revenue on this code.

• A missing laterality modifier, either -RT or -LT.
• Operative documentation that never states the single-compartment scope.
• Reporting 25118 with 25119 for the same wrist, when 25119 already covers that synovectomy.
• An E/M visit billed inside the 90-day global period without modifier -24.

How claims management software keeps CPT 25118 claims clean

In most hand surgery practices, the facts that decide this code sit in different places. The compartment count and the distal ulna decision live in the operative note. The claim is built somewhere else, often days later, by someone who was not in the room.

Practice management software like Pabau keeps the operative note and the claim on one patient record. A coder can confirm single-compartment scope and check whether the ulna was resected. That is enough to separate 25118 from 25119 without a query back to the surgeon.

The 90-day global period gets the same treatment. Post-op appointments stay visible against the surgery date. An E/M code can be held back, or given modifier -24, before the claim reaches the payer. Every Pabau subscription includes the medical records management, claims, and scheduling tools involved.

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Conclusion

CPT code 25118 is a narrowly scoped surgical code where documentation precision decides whether the claim survives. Three details carry most of the risk. Confirm single-compartment scope, append the correct laterality modifier, and check whether the distal ulna was resected.

After that, the 90-day global period separates a high first-pass acceptance rate from a queue of recoverable denials. That is a revenue cycle management problem as much as a coding one. Every post-op encounter for three months has to be checked against the surgery date.

Practices handling a high volume of surgical wrist codes need those checks inside the system that already holds the operative note. Pabau supports orthopedic and hand surgery billing teams with pre-submission claim checks, modifier tracking, and post-operative billing windows.

The right practice management platform is the difference between predictable collections and a backlog of fixable denials. To see how Pabau fits a hand surgery billing workflow, book a demo.

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