CPT code 23405 – Tenotomy, shoulder area, single tendon

Key Takeaways

CPT code 23405 covers open tenotomy of a single tendon in the shoulder, not arthroscopic approaches

When multiple tendons are released in the same session, bill CPT 23406 with Modifier 51 on the secondary code

Arthroscopic tenotomy requires CPT 29999 (unlisted) or an applicable arthroscopy code, not 23405

Laterality modifiers (-LT/-RT) are required by most payers; missing them is the leading denial trigger

Pabau’s claims management software routes shoulder procedure claims through clearinghouse validation before submission

CPT code 23405: official descriptor and procedure overview

CPT code 23405 is defined by the American Medical Association as “Tenotomy, shoulder area; single tendon.” The procedure involves sharply dividing a single tendon in the shoulder region via an open or percutaneous approach. The code sits within the Musculoskeletal System chapter of the CPT codebook, under the Surgery section.

Two codes cover shoulder tenotomy. CPT 23405 applies when the surgeon releases one tendon. CPT 23406 applies when two or more tendons are released during the same surgical session. Selecting between them depends entirely on the operative report, not on the diagnosis or pre-operative plan.

Clinical indications: when is CPT 23405 medically necessary?

CPT code 23405 is medically necessary when conservative measures have failed and surgical release of a single shoulder tendon is required to reduce pain or restore function. Orthopedic practices billing sports medicine and surgical shoulder procedures encounter this code most frequently for biceps pathology and rotator cuff involvement.

Common clinical conditions that support the code:

• Biceps tenosynovitis: Inflammation and thickening of the long head of the biceps tendon that does not resolve with physical therapy or steroid injection. Supported by ICD-10 code M75.2 (Bicipital tendinitis).
• Irreparable rotator cuff tear: When the supraspinatus or subscapularis cannot be repaired, the biceps may be released as part of pain management. Supported by ICD-10 M75.1 (Rotator cuff syndrome).
• SLAP lesion: Superior labrum anterior to posterior tears involving the biceps anchor may be managed with biceps tenotomy. Supported by ICD-10 S43.49 (Other sprain of shoulder joint).
• Failed biceps tendon repair: Re-release of a previously repaired tendon after documented re-rupture or failed healing.

Payer Local Coverage Determinations (LCDs) published by Medicare Administrative Contractors specify the diagnosis codes that must accompany CPT code 23405. Verify the applicable LCD for your MAC before submission, as covered diagnoses vary by jurisdiction.

Surgical technique and operative documentation requirements

CPT code 23405 is an open procedure. The surgeon makes a direct incision over the shoulder to access and sharply divide the target tendon. The operative report is the single most critical document for claim support, and missing elements are the primary reason payers deny or downcode this claim.

The operative report must contain all of the following to support CPT 23405:

• Confirmation that the procedure was performed via an open approach (not arthroscopic)
• The name of the specific tendon released (e.g., long head of biceps, subscapularis)
• Confirmation that only one tendon was divided
• Patient positioning and anaesthesia type
• Instruments used for the division (scalpel, electrocautery, or other)
• Closure technique and layer-by-layer closure detail

A clean claim for CPT 23405 depends on this documentation being present before the claim is submitted, not added after a denial. Coders should request the full op report before coding, not rely on the pre-operative diagnosis alone.

CPT 23405 vs. 23406: single vs. multiple tenotomy

The difference between CPT 23405 and CPT 23406 is the tendon count confirmed in the operative report, nothing more. A surgeon who releases the long head of biceps and the subscapularis in the same session has performed multiple tenotomies; bill CPT 23406 with Modifier 51 appended.

Modifier 51 signals to the payer that multiple procedures were performed during one surgical session. Apply it to the lower-value code (23406 when billed alongside a higher-valued rotator cuff repair). Failure to append Modifier 51 when multiple procedures are billed together commonly triggers an NCCI edit denial.

CPT 23405 vs. 29999: open vs. arthroscopic tenotomy

CPT 23405 applies exclusively to open or percutaneous tenotomy; arthroscopic tenotomy does not map to this code. This is the most consequential coding error for shoulder tenotomy claims, and the AAPC has published specific guidance on the 23405-vs-29999 selection.

When the surgeon performs a biceps tenotomy entirely through arthroscopic portals, the appropriate code is CPT 29999 (Unlisted procedure, arthroscopy). The claim for 29999 requires submission of the operative report alongside the claim because payers cannot price an unlisted code without reviewing the documentation. Some Medicare Administrative Contractors have accepted CPT 29827 (arthroscopic repair of massive rotator cuff tear) when tenotomy is performed as an integral component, but this requires careful documentation review and MAC-specific policy verification.

The documentation marker that drives code selection is straightforward: if the op report describes portal placement, arthroscopic visualization, and instrument insertion through cannulas, the procedure is arthroscopic and CPT 23405 does not apply.

CPT 23405 vs. tenodesis (CPT 23430): choosing the correct code

Tenotomy and tenodesis are opposite surgical acts: tenotomy divides and releases the tendon, while tenodesis reattaches the tendon to a new anchor point. Coders frequently confuse these two procedures because both involve the biceps tendon and often share the same operative setting.

If the operative report documents both division and reattachment in the same surgical site, the tenodesis code takes precedence. Billing CPT code 23405 when the surgeon performed a tenodesis understates the service and may be flagged during a payer audit as a pattern of undercoding.

Billing CPT code 23405 with other shoulder codes: bundling rules

CPT code 23405 can be billed alongside certain shoulder arthroscopy and debridement codes, but specific NCCI edits and modifier requirements apply. The AAPC has confirmed that tenotomy and debridement can be billed together when the debridement is a separate and distinct procedure, not incidental to the tenotomy itself.

• CPT 29826 (subacromial decompression): May be billed with CPT code 23405 when performed as a distinct arthroscopic procedure accompanying an open tenotomy. Append Modifier 51 to the lower-value code. Verify current NCCI edit status before billing.
• CPT 29822 / 29823 (shoulder debridement): Billed with CPT code 23405 when debridement is performed in an anatomically distinct area and documented separately. Modifier 59 or XS may be required to override the NCCI edit, depending on the code pair.
• Rotator cuff repair codes (23410, 23412, 29827): When tenotomy accompanies a rotator cuff repair, payers often bundle 23405 as incidental to the repair. Document medical necessity separately for the tenotomy and consult payer-specific policies before unbundling.

Submitting claims through Pabau’s Claim.MD clearinghouse integration applies real-time NCCI edit checks before shoulder procedure claims reach the payer, catching bundling conflicts before they become denials.

Applicable modifiers for CPT code 23405

Most payers require at least one modifier on every shoulder surgery claim. Missing modifiers are the second most common denial trigger for CPT code 23405, behind approach mismatch.

Medicare reimbursement and CPT code 23405 fee schedule

Medicare reimburses CPT code 23405 under the Medicare Physician Fee Schedule (MPFS). Payment amounts differ by setting: facility rates apply when the procedure is performed in a hospital or ambulatory surgical center; non-facility rates apply in an office setting.

The 2025 national Medicare non-facility rate for CPT code 23405 is approximately $623 before geographic adjustment. The facility rate is lower, approximately $361, because Medicare pays the facility separately for overhead costs. These figures are national averages; the Geographic Practice Cost Index (GPCI) adjusts the final payment based on the location of service. Use the CMS Physician Fee Schedule lookup tool for locality-specific current rates, as figures update with each annual MPFS rule.

RVU values are published annually. Use the FastRVU lookup tool or the CMS data files for current-year figures. Commercial payer rates typically exceed Medicare by 110% to 160%, though contracts vary significantly by region and payer.

Pabau’s claims management software tracks paid amounts against expected fee schedule values so orthopedic practices can identify underpayments on CPT code 23405 without manually cross-referencing each ERA. Claims routed via Pabau’s Claim.MD clearinghouse integration receive electronic remittance advice in 835 format, making variance tracking straightforward.

Prior authorization requirements for CPT 23405

Medicare does not require prior authorization for CPT code 23405 in most circumstances, but most commercial payers do. Requirements vary by plan, and authorization rules for shoulder surgeries change frequently, so verify with each payer before scheduling.

When a commercial payer requires prior auth, the clinical documentation package typically must include:

• Documented conservative treatment failure (minimum 6 weeks of physical therapy or steroid injection in most plans)
• Imaging confirming the pathology (MRI or ultrasound identifying the specific tendon involved)
• Surgeon attestation of medical necessity with the planned approach (open vs. arthroscopic clearly stated)
• Supporting ICD-10 diagnosis codes that are on the payer’s covered-diagnosis list

Submitting an auth request that states the approach as “arthroscopic” when the surgeon plans to perform an open tenotomy (CPT code 23405) can result in a denied claim even if the auth was approved, because the authorized service will not match the billed service. Document the planned approach precisely in the auth request. For guidance on maintaining medical billing compliance across payer requirements, see Pabau’s compliance reference.

Common claim denial reasons for CPT code 23405 and how to avoid them

Denials for CPT code 23405 concentrate around a small set of recurring errors. Most are preventable with front-end documentation checks before the claim is submitted.

• Wrong approach coded: The most common error. Billing CPT code 23405 for a procedure that the op report describes as arthroscopic. Fix: coders must read the approach section of the operative report, not just the pre-operative diagnosis.
• Missing laterality modifier: Shoulder procedures require -LT or -RT. Submitting without a laterality modifier causes automatic claim rejection by most clearinghouses and payers. Fix: build laterality into the claim template for all shoulder codes.
• ICD-10 diagnosis mismatch: The diagnosis code submitted does not appear on the MAC’s LCD for shoulder tenotomy. Fix: cross-reference the LCD before finalising the claim. Common covered codes include M75.2, M75.1, and M66.211.
• Insufficient conservative treatment documentation: Commercial payers require evidence of failed non-surgical management. Fix: attach physical therapy notes, injection records, or failed conservative treatment attestation to the claim or auth request.
• Bundling error with concurrent procedures: Billing CPT code 23405 alongside a rotator cuff repair code without reviewing NCCI edits for the pair, resulting in the tenotomy being denied as bundled. Fix: check the NCCI edit table for the specific code pair and apply modifiers where edits are bypassable.

For a systematic approach to appealing denied shoulder procedure claims, see Pabau’s guide to denial management in healthcare and the reference on denial codes in medical billing.

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Conclusion

CPT code 23405 is a straightforward code with a narrow set of failure points: approach documentation, laterality modifiers, and diagnosis code alignment. Most denials are not complex disputes but preventable front-end errors that a pre-submission check catches in seconds.

Pabau’s claims management platform runs NCCI edit validation, clearinghouse checks, and ERA reconciliation on shoulder procedure claims before and after submission, giving orthopedic coding teams a faster path to clean claims on CPT code 23405 and related shoulder codes. To see it in action, book a demo.

Continue your research

Need a reference for clearinghouse claim submission? Pabau’s Claim.MD clearinghouse guide explains how electronic claim submission works for surgical procedure codes.

Want to understand 837 file formats for surgical claims? Understanding the 837 claim file covers how procedure codes, modifiers, and diagnosis codes are structured in electronic submissions.

Exploring eligibility verification before surgery scheduling? Insurance eligibility verification outlines how to confirm prior authorization requirements and covered diagnoses before the procedure date.

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