ModifiedPremera BluecrossPolicy 7.01.595

Carpal Tunnel Release Surgical Techniques

Defines medical necessity, site-of-service review, documentation, investigational techniques, and coding for endoscopic and open carpal tunnel release surgery for carpal tunnel syndrome for Premera Bluecross members (excludes Medicare Advantage).

Policy Summary

PayerPremera Bluecross

PolicyCarpal Tunnel Release Surgical Techniques

Policy CodePolicy 7.01.595

Change TypeModified (site-of-service criteria added; criteria simplified; new CPT added)

Effective DateJun 5, 2026

Next Review Date

Key ActionSubmit office visit notes showing either electrodiagnostic testing results confirming carpal tunnel syndrome or CTS-6 score > 12 to support medical necessity review

SourceLink

POLICY UPDATE CHANGES

Site of Service Ambulatory Service Center (ASC) Select Diagnostic or Surgical Procedures criteria added, effective for dates of service on or after June 5, 2026 following 90-day provider notification.

Carpal tunnel release surgery medical necessity criteria simplified to require either electrodiagnostic confirmation or CTS-6 >12; added investigational status for ultrasound-guided percutaneous intracarpal tunnel balloon dilation release.

CPT code 64728 added, effective 01/01/26.

Provocative tests and CTS-6 included to simplify medical necessity review (interim review 12/01/25).

Added header that site of service review does not apply to Indian Health Services (IHS) facilities (06/01/26).

2Surgical approaches covered

3Techniques labeled investigational

1New CPT code added (2026-01-01)

90Provider notification days before effective date

Coverage Summary

Scope: This policy defines medical necessity, site-of-service review, documentation, and coding for open and endoscopic carpal tunnel release surgery for carpal tunnel syndrome (Premera Blue Cross members; excludes Medicare Advantage).

Coverage stance: Mixed — endoscopic and open carpal tunnel release are covered when medical necessity criteria are met; several newer minimally invasive techniques are labeled investigational and not covered.

What the policy defines: medical necessity criteria for carpal tunnel release (requirements for diagnostic confirmation and conservative therapy), site-of-service guidance preferring Ambulatory Surgical Center (ASC) with precise exceptions for hospital outpatient use, investigational status for thread and ultrasound-guided percutaneous techniques, and coding rules (including addition of CPT 64728 for percutaneous intracarpal tunnel balloon dilation).

Effective date and provider notification: changes (including site-of-service ASC criteria) are effective for dates of service on or after June 5, 2026 following 90-day provider notification; coding update for CPT 64728 effective 01/01/26.

Key thresholds & quick facts

CTS-6 score threshold> 12

Conservative treatment duration>= 6 weeks (unless severe findings present)

Prolonged surgery (site-of-service risk)> 3 hours

Morbid obesity (site-of-service)BMI >= 50

Advanced liver disease (site-of-service)MELD Score > 8

COPD / pulmonary function thresholdFEV1 < 50%

Poorly controlled asthma thresholdFEV1 < 80% despite treatment

Provider notification before effective date90 days

Medical Necessity Criteria

Site of Service & Provider Actions

Prior Authorization

Site of service review / prior review

Site of service for elective diagnostic or surgical procedures will be reviewed for medical necessity. Ambulatory surgical center (ASC) is the preferred site of service. Hospital outpatient may be considered medically necessary only when ASC is not accessible or clinical considerations exist. This site-of-service review does not apply to Indian Health Services (IHS) facilities. Changes effective for dates of service on or after June 5, 2026.

No qualifying ASC within 30 miles that can provide the necessary care (example: nearest ASC >30 miles)
Qualifying ASC lacks necessary equipment or the physician lacks privileges at the ASC
Concurrent service requiring hospital outpatient department performed in the same operative session

Documentation Required

Coding

Covered / Relevant CPT codes for carpal tunnel releaseCPTCovered

29848	Endoscopy, wrist, surgical, with release of transverse carpal ligament
64721	Neuroplasty and/or transposition; median nerve at carpal tunnel
25999	Unlisted procedure, forearm or wrist
64999	Unlisted procedure, nervous system
64728	Decompression; median nerve at the carpal tunnel, percutaneous with intracarpal tunnel balloon dilation, including ultrasound guidance (new code effective 01/01/26)

Background and Evidence

Background: Carpal tunnel syndrome results from compression of the median nerve in the wrist and produces numbness, tingling, pain, and weakness in the median-innervated fingers; it is common and may worsen over time.

Conservative management: initial non-surgical treatments include night hand immobilization (splinting), corticosteroid injection, NSAIDs or oral steroids, and other conservative measures. The policy requires at least 6 weeks of conservative therapy (night splinting and/or corticosteroid injection) before surgery unless severe findings (for example thenar wasting or impaired two-point discrimination) are present.

Surgical options: when conservative care fails, both open and endoscopic carpal tunnel release are described — cutting the transverse carpal ligament to relieve median nerve pressure — and the evidence supports that open and endoscopic approaches are approximately equally effective, with endoscopic possibly offering quicker return to work and fewer minor complications.

Newer techniques: two less-invasive procedures — thread carpal tunnel release and ultrasound-guided percutaneous releases (including percutaneous intracarpal tunnel balloon dilation) — are discussed but have limited and small studies; these techniques are considered investigational per the policy.

Documentation and coding notes: electrodiagnostic testing is recommended prior to surgery to confirm diagnosis; the policy lists applicable CPT codes and notes the addition of CPT 64728 for percutaneous intracarpal tunnel balloon dilation (effective 01/01/26).

Evidence Type	Summary
Systematic reviews/meta-analyses	Numerous systematic reviews and meta-analyses of randomized trials show open and endoscopic release are about equally effective; endoscopic may have quicker return to work, fewer minor complications, and possible grip strength benefit.
Corticosteroid injection effect	Injection of corticosteroid provides short-term symptom relief and may delay surgery, but does not provide long-term improvement.
Insufficient evidence	Thread carpal tunnel release and ultrasound-guided percutaneous techniques have limited small studies and are considered investigational; additional well-designed studies are needed.

Definitions (term -> definition)

Revision History

2026-06-05site_of_service_changeLatest

Site of Service Ambulatory Surgical Center (ASC) criteria added: ASC preferred; hospital outpatient may be medically necessary only when ASC not accessible or clinical considerations exist. Site-of-service criteria do not apply to Indian Health Services (IHS) facilities; change effective for dates of service on or after June 5, 2026 following 90-day provider notification.

2026-06-05medical_necessity_revisionLatest

Carpal tunnel release surgery medical necessity criteria simplified: clinical diagnosis must be supported by either electrodiagnostic confirmation or CTS-6 score >12; added investigational status for ultrasound-guided percutaneous intracarpal tunnel balloon dilation release; effective for dates of service on or after June 5, 2026.

Policy Summary

PayerPremera Bluecross

PolicyCarpal Tunnel Release Surgical Techniques

Policy CodePolicy 7.01.595

Change TypeModified (site-of-service criteria added; criteria simplified; new CPT added)

Effective DateJun 5, 2026

Next Review Date

Key ActionSubmit office visit notes showing either electrodiagnostic testing results confirming carpal tunnel syndrome or CTS-6 score > 12 to support medical necessity review

SourceLink

On This Page

Document diagnostic confirmation

Submit office visit notes that document diagnostic confirmation. Provide either electrodiagnostic testing results (nerve conduction study or electromyography) showing carpal tunnel syndrome OR a CTS-6 score greater than 12.

Documentation Required

Document conservative therapy trial

Document at least 6 weeks of conservative treatment prior to surgical review, including night hand immobilization (splint or brace) and/or a carpal tunnel corticosteroid injection. A trial of conservative care is not required if severe findings are present (thenar wasting, impaired two-point discrimination on the thumb side, or other severe symptoms).

Billing Rule

Use appropriate CPT code

Report the applicable CPT code(s) for the performed procedure. Note that CPT code 64728 (decompression; median nerve at the carpal tunnel, percutaneous with intracarpal tunnel balloon dilation, including ultrasound guidance) was added effective 01/01/26.

29848
64721
64728
25999
64999

Denial Risk

Denial if criteria unmet

Claims for carpal tunnel release may be denied if medical necessity criteria are not met. Specifically, lack of documented diagnostic confirmation (electrodiagnostic results or CTS-6 >12) and/or failure to document the required conservative therapy trial (≥6 weeks unless severe findings present) can result in a finding of not medically necessary and denial.

CTS-6Carpal Tunnel Symptom Scale 6-item evaluation tool; score >12 supports diagnosis per policy

Thenar wastingAtrophy of the muscles in the thenar eminence indicating chronic/severe median nerve compression

ASA classification III or higherAmerican Society of Anesthesiologists physical status indicating severe systemic disease or worse

2026-01-01coding_addition

CPT code 64728 added (Decompression; median nerve at the carpal tunnel, percutaneous with intracarpal tunnel balloon dilation, including ultrasound guidance); new code effective 01/01/26.

2025-12-01clarification

Provocative tests and CTS-6 included to simplify medical necessity review (interim review 12/01/25); policy intent unchanged.

2026-06-01minor_update

Header added clarifying that site of service review does not apply to Indian Health Services (IHS) facilities (06/01/26).