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, coded within the AMA’s Musculoskeletal System section.

Rheumatoid arthritis and tenosynovitis are the most common clinical indications; ICD-10 codes M05.831, M06.031, and M65.031 are frequently linked for medical necessity.

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

CPT 25118 carries a 90-day global surgery period; billing follow-up visits separately during this window without a modifier is a common denial trigger.

Pabau’s claims management software helps orthopedic and hand surgery practices track claim status, apply correct modifiers, and reduce denials for surgical codes like 25118.

Orthopedic and hand surgery billers meet CPT code 25118 after a single-compartment synovectomy at the wrist. Denials on this code come from modifier errors, thin operative documentation, or confusion with neighboring codes. Good plastic surgery and orthopedic practice software flags all three before the claim goes out.

The American Medical Association’s CPT code set places CPT Code 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. In plain terms, the surgeon excises the inflamed synovial lining of one dorsal wrist compartment. The aim is to relieve pain and restore wrist extension.

The “single compartment” qualifier is critical. Six extensor tendon compartments run across the dorsal wrist, each containing distinct tendons. CPT code 25118 covers removal from only one. 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 (corticosteroid injections, splinting, physical therapy) has failed to control synovial inflammation. The procedure is most common in patients whose inflammatory condition is causing pain, swelling, or impaired wrist extension.

Correct use of CPT Code 25118 depends on confirming both the anatomical site (extensor tendon sheath, wrist) and the scope (single compartment). If the clinical scenario does not match those two elements, CPT Code 25118 is the wrong code. For physical therapy practice management teams coordinating conservative care before surgery, documenting the failed conservative treatment course is essential for establishing medical necessity.

• 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. Localized to one compartment to match the single-compartment 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. Pre-authorization should be confirmed for rheumatoid indications before scheduling, as 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 matters: codes ending in “1” indicate the right wrist, “2” the left wrist, and “3” both wrists (bilateral). Use the most specific code available to avoid automatic denials on specificity grounds. Coders should review the ICD-10-CM diagnosis coding guidelines for laterality conventions before finalizing the claim. The table below maps the most common diagnosis codes linked to this procedure. The same ICD-10 crosswalk reference method works for other surgical code lookups.

Verify each code against current CMS ICD-10-CM guidelines before filing. Payer LCD/NCD policies vary: a specific ICD-10 code does not guarantee coverage or approval. Some commercial payers require additional specificity at the 7th-character level where available.

Reimbursement rates and Medicare fee schedule for CPT code 25118

Medicare reimbursement for CPT Code 25118 is calculated using the Resource-Based Relative Value Scale (RBRVS). The total payment reflects three RVU components multiplied by the annual Conversion Factor and adjusted for geographic location via the Geographic Practice Cost Index (GPCI).

Rates differ between facility and non-facility settings because practice expense RVUs are higher in office (non-facility) settings.

Use the CMS Physician Fee Schedule lookup tool to pull locality-specific rates for the current year. The table below presents approximate national average values based on current Medicare Physician Fee Schedule data. Rates change annually, so verify current figures directly with CMS before billing. Teams looking for real-time RVU values can use the FastRVU 2026 RVU lookup tool for a quick reference.

RVU breakdown for CPT 25118

*Approximate values based on available MPFS data. Actual reimbursement varies by locality and year. Multiply total RVUs by the current Medicare Conversion Factor and apply the relevant GPCI to get the locality-adjusted payment rate. Commercial payer rates are negotiated separately and are typically a percentage of Medicare.

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. Verify current NCCI edits before billing: The AAPC Codify CPT lookup includes modifier guidance and NCCI indicator checks for each code.

Note that CMS updates NCCI edits quarterly, so modifier applicability should be confirmed against the current tables.

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. Train front desk and billing staff to flag any post-operative appointment for 25118 patients and apply the correct modifier before claim submission.

CPT 25118 vs. CPT 25119: Key differences

The most frequent coding question around CPT code 25118 is how it differs from CPT 25119. Both codes describe the same single-compartment synovectomy of the extensor tendon sheath at the wrist. The difference is bone work. CPT 25119 also includes resection of the distal ulna, known as a Darrach-type resection. Nothing in 25119 signals a wider synovectomy, so coders who read it as the extensive version of 25118 pick the wrong code. Refer to a broader CPT procedure code reference for the general framework on how CPT distinguishes surgical scope across related codes.

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 instead of billing the two codes together. If the note describes radical tenosynovectomy across several sheaths, move to CPT 25115 or CPT 25116. Choosing a code because it looks closer to the surgeon’s description, without documentation support, is a compliance risk.

Related CPT codes in the forearm and wrist section

Orthopedic and hand surgery billing teams frequently encounter CPT Code 25118 alongside companion codes in the same anatomical grouping. Understanding the full code family helps prevent under-coding, over-coding, and bundling errors. Other specialties organize their codes the same way. IVF billing uses a structured family of surgical codes where scope drives the choice, as the reproductive procedure CPT codes reference shows.

Billing and documentation requirements for CPT code 25118

Documentation gaps are the primary reason CPT code 25118 claims are denied on audit rather than at initial submission. The operative report must support the code selection before the claim is filed. Practices using claims management software can build pre-submission checklists that flag missing operative report elements before a claim leaves the system. Maintaining HIPAA compliance for medical offices also requires that operative documentation is stored securely and retrievable for payer audits.

Operative report requirements

• Anatomical site: Explicitly name “extensor tendon sheath” and “wrist.” Generic wrist surgery language is insufficient.
• Compartment count: State the specific compartment number (e.g., “first extensor compartment”) or describe that only a single compartment was addressed. This is the documented basis for choosing 25118 over the radical codes 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 encountered and the amount of tissue excised.
• Laterality: Right or left wrist clearly stated in the operative header and body of the report.
• Clinical indication: Cite the diagnosis (e.g., rheumatoid tenosynovitis, PVNS) and note failure of conservative treatment if applicable.

Pre-authorization and common denial reasons

Pre-authorization is required by many commercial payers for CPT code 25118. Submit the authorization request with the operative plan, supporting ICD-10 code, and documentation of prior conservative treatment. Medicare does not require pre-authorization for this code, but documentation must still 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.

Hand surgery billers who cross-code across specialties can also review CPT documentation requirements to see how payers evaluate medical necessity narratives across code types.

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 sending 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 claims, records, 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 before choosing between 25118 and 25119.

After that, the 90-day global period is what separates a high first-pass acceptance rate from a queue of recoverable denials. Every post-op encounter for three months has to be checked against it.

Practices handling a high volume of surgical wrist codes need those checks inside the system that already holds the operative note. Pabau’s claims management software 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 a predictable revenue cycle and a backlog of fixable denials. To see how Pabau fits a hand surgery billing workflow, book a demo.

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