ModifiedBlue Cross Blue Shield - OklahomaPolicy CPCPLAB064

Nerve Fiber Density Testing

Laboratory management and reimbursement criteria for epidermal nerve fiber density testing (skin biopsy) for diagnosis of small-fiber (painful sensory) neuropathy for BCBSOK members; describes when testing is reimbursable and codes related to the procedure.

Policy Summary

PayerBlue Cross Blue Shield - Oklahoma

PolicyNerve Fiber Density Testing

Policy CodePolicy CPCPLAB064

Change TypeMaterial reimbursement code update + reference updates

Effective DateMarch 1, 2024

Next Review DateN/A

Key ActionUse the updated billing guidance and current code set (including added code 88313) and verify prior authorization rules when submitting claims.

SourceLink

POLICY UPDATE CHANGES

Reimbursement information revised for clarity and code list updated: added code 88313; removed codes 88305, 88314.

Document updated with literature review and references revised.

1Policy version

Mar 1, 2024Plan effective date

7Listed procedure/billing codes

88313Code added

88305,88314

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Coverage Criteria

Reimbursable indications (Initial diagnostic testing)

Epidermal nerve fiber density measurement from a skin biopsy may be reimbursable when ALL of the following are met:

Diagnostic criteria for reimbursable ENFD: a. An individual presents with symptoms of painful sensory neuropathy; b. 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); c. 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; d. Electromyography and nerve-conduction studies are normal and show no evidence of large-fiber neuropathy.ALL required

All four conditions must be met for reimbursement.

For all situations not specifically described as reimbursable under this policy, epidermal nerve fiber density (ENFD) measurement from a skin biopsy is not reimbursable. Claims that do not meet the diagnostic criteria listed for initial diagnostic testing should be expected to be denied unless documentation clearly demonstrates that ALL required conditions are satisfied.

Measurement of sweat gland nerve fiber density is explicitly excluded from reimbursement under this policy and is not reimbursable.

The policy reimbursement information was revised in the 03/01/2024 update to clarify billing guidance and the listed code set. This document segment does not add new clinical coverage rules but does note operational billing code changes that may affect claim submission.

No additional clinical coverage statements or not-medically-necessary determinations are specified in this partial document segment.

Procedure and Billing Codes

Procedure / pathology codes listedCPT

88313
88341
88342
88344
88346
88350
88356

Reimbursement code changesmixed

88313	Added laboratory/pathology code (as listed in reimbursement update)
88305	Removed code (previously listed)
88314	Removed code (previously listed)

Provider Actions and Billing Guidance

Prior Authorization

Prior Authorization — Not Specified

Prior authorization requirement not specified in this document. Providers should verify member-specific benefit coverage and any plan or contract level prior authorization rules prior to service delivery.

Prior authorization: Not specified in this policy — check member's plan documents and provider contract for any PA requirements.

Billing Rule

Billing Code Update — Verify PA Rules

Billing codes for this policy were updated effective 03/01/2024. Providers must bill using the current valid CPT/HCPCS codes and follow any applicable prior authorization rules tied to those codes.

Added CPT 88313
Removed CPT 88305 and CPT 88314

Background

Epidermal nerve fiber density (ENFD) measurement from a skin biopsy is a quantitative pathology test used to evaluate small‑fiber neuropathy, particularly when patients present with painful sensory symptoms but have normal large‑fiber testing (electromyography and nerve conduction studies). The policy limits reimbursement to diagnostic situations where ALL of the following are met: (1) symptoms of painful sensory neuropathy; (2) no history of a disorder known to predispose to painful neuropathy (for example, diabetic, toxic, HIV, celiac, or inherited neuropathies); (3) physical examination without findings of large‑fiber neuropathy (such as reduced/absent reflexes or impaired proprioception/vibration); and (4) normal electromyography and nerve‑conduction studies showing no large‑fiber neuropathy. The 03/01/2024 update also revised reimbursement wording and the code list (added 88313 and removed 88305 and 88314), so providers should ensure billing uses the current code set when submitting claims.

Definitions

Small-fiber neuropathy — definition and clinical presentation

DefinitionSmall-fiber neuropathy: a neuropathy affecting small sensory fibers, typically presenting with painful sensory symptoms, where large-fiber studies (EMG/nerve conduction) are normal.

Typical clinical presentationSymptoms of painful sensory neuropathy (e.g., burning pain, dysesthesias) in the absence of signs of large-fiber involvement.

Examination findings required for reimbursementNo evidence of large-fiber neuropathy on physical exam — e.g., preserved muscle-stretch reflexes and intact proprioception and vibration sensation.

ElectrophysiologyElectromyography and nerve-conduction studies must be normal and show no evidence of large-fiber neuropathy for testing to be reimbursable.

Exclusions relevant to diagnosisA history of disorders known to predispose to painful neuropathy (for example diabetic, toxic, HIV, celiac, or inherited neuropathies) excludes reimbursable testing under the policy.

Policy Summary

PayerBlue Cross Blue Shield - Oklahoma

PolicyNerve Fiber Density Testing

Policy CodePolicy CPCPLAB064

Change TypeMaterial reimbursement code update + reference updates

Effective DateMarch 1, 2024

Next Review DateN/A

Key ActionUse the updated billing guidance and current code set (including added code 88313) and verify prior authorization rules when submitting claims.

SourceLink

On This Page

Verify prior authorization rules that may apply to the updated codes with payer-specific claim guidance

Step Therapy

Step Therapy — None Stated

No step therapy requirements are stated in this policy for epidermal nerve fiber density measurement or related services.

Step therapy: None stated

Documentation Required

Documentation and Support for Medical Necessity

Providers are responsible for submission of accurate documentation to support medical necessity. Ensure claims include pertinent clinical information (symptoms, exam findings, EMG/nerve conduction study results, and absence of conditions predisposing to large-fiber neuropathy) when requesting reimbursement for epidermal nerve fiber density measurement.

Documentation must show: painful sensory neuropathy symptoms; no history of disorders that predispose to painful neuropathy; physical exam without large-fiber neuropathy signs; normal EMG/nerve conduction studies
Upon request, submit additional documentation to support medical necessity

Denial Risk

Denial Risk — Billing/Coding and Clinical Criteria

Use of codes removed from the policy effective 03/01/2024 or failure to include newly added codes may trigger claim denials or require claim resubmission. Denials may also occur for services performed outside the stated medically necessary criteria or for sweat gland nerve fiber density testing, which is not reimbursable.

Denial triggers: use of removed codes (88305, 88314) or omission of added code (88313)
Denial triggers: testing for sweat gland nerve fiber density (not reimbursable)
Denial triggers: services not meeting the Reimbursement Information criteria

Epidermal Nerve Fiber Density (ENFD) — definition and role in diagnosis

DefinitionEpidermal Nerve Fiber Density (ENFD): a quantitative measure from a skin biopsy assessing small sensory nerve fiber density used to diagnose small-fiber neuropathy.

Role in diagnosisENFD measurement from skin biopsy is used to support diagnosis of small-fiber neuropathy when clinical criteria are met and large-fiber testing is normal.

When reimbursableReimbursable only if ALL policy criteria are met: symptoms of painful sensory neuropathy; no history of disorders that predispose to painful neuropathy; no physical exam evidence of large-fiber neuropathy; and normal EMG/nerve-conduction studies.

Limitations and exclusionsMeasurement of sweat gland nerve fiber density is not reimbursable per the policy; ENFD testing is not reimbursable for situations not meeting the listed criteria.

Supporting evidencePolicy cites peer-reviewed literature and reference studies (e.g., epidermal nerve fiber quantification and analyses improving diagnostic yield) as supporting evidence for ENFD utility.