CurrentBlue Cross Blue Shield - OklahomaPolicy CPCPLAB064

Nerve Fiber Density Testing

Defines reimbursement criteria and coding/billing guidance for epidermal nerve fiber density (ENFD) testing from skin biopsy for diagnosis of small-fiber neuropathy, and states non-reimbursement for other uses including sweat gland nerve fiber density.

Policy Summary

PayerBlue Cross Blue Shield - Oklahoma

PolicyNerve Fiber Density Testing

Policy CodePolicy CPCPLAB064

Change TypeClarified; Revised (historical)

Effective DateMay 1, 2026

Next Review DateN/A

Key ActionDocument symptoms, exam findings, absence of predisposing disorders, and normal EMG/nerve conduction studies and submit accurate documentation with valid codes to support reimbursement.

SourceLink

POLICY UPDATE CHANGES

01/12/2026 document updated with literature review; Reimbursement Information unchanged; References revised.

03/01/2024 reimbursement information revised for clarity; added code 88313; removed codes 88305 and 88314.

11/1/2022 New policy created.

1Covered Indications (conditional)

1Not Reimbursable: sweat gland nerve fiber density

3Required negative/absence findings for coverage

Policy overview

This policy (Policy Number: CPCPLAB064) defines reimbursement criteria and coding/billing guidance for epidermal nerve fiber density (ENFD) testing from skin biopsy to diagnose small-fiber neuropathy. The policy summarizes medically reimbursable indications and explicit non-reimbursable uses (e.g., sweat gland nerve fiber density) and states that not all requirements apply to each product — plan documents govern coverage specifics and prevail in case of conflict. Evidence informing the policy includes Practice Parameters and guidelines from organizations such as the American Academy of Neurology (AAN), the European Federation of Neurological Societies (EFNS), and multiple peer-reviewed studies and reviews.

Subject: Nerve Fiber Density Testing (epidermal nerve fiber density from skin biopsy); Coverage stance: mixed; Status: CURRENT.

Policy header

Effective date2026-05-01

Last review2026-01-12

Next review

PayerBlue Cross Blue Shield - Oklahoma

Policy titleNerve Fiber Density Testing

Policy numberCPCPLAB064

Scope summaryDefines reimbursement criteria and coding/billing guidance for epidermal nerve fiber density (ENFD) testing from skin biopsy for diagnosis of small-fiber neuropathy, and states non-reimbursement for other uses including sweat gland nerve fiber density.

Coverage criteria (when ENFD testing is reimbursable)

Medically Reimbursable Indication for ENFD Testing

ENFD measurement from skin biopsy may be reimbursable when ALL of the following conditions are met:

ALL of the following

An individual presents with symptoms of painful sensory neuropathy
There is no history of a disorder known to predispose to painful neuropathy (e.g., diabetic neuropathy, toxic neuropathy, HIV neuropathy, celiac neuropathy, inherited neuropathy)
Physical examination shows no evidence of findings consistent with large-fiber neuropathy, such as reduced or absent muscle-stretch reflexes or reduced proprioception and vibration sensation
Electromyography and nerve-conduction studies are normal and show no evidence of large-fiber neuropathy

Not Reimbursable

Not reimbursable

ANY of the following

Epidermal nerve fiber density measurement from a skin biopsy for situations not meeting the above criteria (i.e., all other situations)
Measurement of sweat gland nerve fiber density

Code lists and coding notes

Procedure Codes (document notes code list is not all-encompassing)CPT

No codes listed

Pathology / Addendum codes changed in historyCPT

88313	Code added to policy in 03/01/2024 update (document history)
88305	Code removed from policy in 03/01/2024 update (document history)
88314	Code removed from policy in 03/01/2024 update (document history)

Providers must submit accurate documentation of services and submit claims using valid code combinations from HIPAA-approved code sets, following standard industry coding guidelines (e.g., CPT, ICD-10, CMS CCI edits). Claims are subject to code edit protocols and review and providers may be asked to supply additional documentation.

Document history shows code changes on 03/01/2024: added CPT 88313 and removed CPT 88305 and 88314.

Billing, documentation, and denial risk

Billing Rule

Submit accurate documentation and valid codes

Providers must submit accurate documentation of services and submit claims using valid code combinations from HIPAA‑approved code sets and follow standard coding guidelines; claims are subject to code edit protocols and review.

Valid code combinations from HIPAA‑approved code sets
Industry-standard coding guidelines (e.g., CPT, HCPCS, ICD-10)
Claims subject to code edit protocols and claim review

Documentation Required

Clinical documentation to support medical necessity

Document that the patient has symptoms of painful sensory neuropathy; explicitly note absence of disorders known to predispose to painful neuropathy (for example: diabetic neuropathy, toxic neuropathy, HIV neuropathy, celiac neuropathy, inherited neuropathy); record physical exam findings that show no evidence of large‑fiber neuropathy (eg, preserved muscle‑stretch reflexes, intact proprioception and vibration); and include normal electromyography and nerve‑conduction study results demonstrating no large‑fiber neuropathy to support reimbursement.

Denial Risk

Not reimbursable outside specified criteria

Claims that do not meet ALL listed reimbursement criteria (the required symptom, absence of predisposing disorders, exam excluding large‑fiber neuropathy, and normal EMG/nerve‑conduction studies) and claims for measurement of sweat gland nerve fiber density are not reimbursable and may be denied.

Key definitions

Definitions

TermENFD

DefinitionEpidermal nerve fiber density measurement from skin biopsy for diagnosis of small-fiber neuropathy.

Clarifying noteENFD testing may be reimbursable only when all specified clinical criteria are met (symptoms of painful sensory neuropathy; no history of predisposing disorders; absence of large-fiber neuropathy on exam; normal EMG/nerve conduction studies).

Evidence and guideline references

Practice Parameter / Guidelines cited: Multiple guideline and literature references support the use of skin biopsy (ENFD measurement) for diagnosis of small-fiber neuropathy, including AAN practice parameters and EFNS/PNS guidelines, along with numerous peer‑reviewed studies and reviews that establish diagnostic utility and normative data.

These referenced guidelines and studies inform the policy’s reimbursement criteria, but plan documents determine product applicability and govern coverage in case of conflict.

Document revision history

2022-11-01added

New policy created

2024-03-01revised

Reimbursement information revised for clarity; added code 88313; removed codes 88305 and 88314

2026-01-12clarifiedLatest

Document updated with literature review; Reimbursement Information unchanged; References revised.

Policy Summary

PayerBlue Cross Blue Shield - Oklahoma

PolicyNerve Fiber Density Testing

Policy CodePolicy CPCPLAB064

Change TypeClarified; Revised (historical)

Effective DateMay 1, 2026

Next Review DateN/A

Key ActionDocument symptoms, exam findings, absence of predisposing disorders, and normal EMG/nerve conduction studies and submit accurate documentation with valid codes to support reimbursement.

SourceLink

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