CurrentBlue KCPolicy POL-PP-296

Onychomycosis Testing Payment Policy

Defines Blue KC payment/reimbursement stance for laboratory tests used to diagnose or confirm onychomycosis (nail fungal infection) and the providers/facilities and lines of business affected.

Policy Summary

PayerBlue KC

PolicyOnychomycosis Testing Payment Policy

Policy CodePolicy POL-PP-296

Change TypeNo material changes

Effective Date07/01/2025

Next Review Date07/01/2026

Key ActionReimburse KOH microscopy, fungal culture, and fungal stain; reimburse NAAT only after antifungal therapy failure; ATR-FTIR and fungal sterol testing are not reimbursed.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

001version

07/01/2025effective

07/01/2026next review

Commercial, MA, ACA QHP, Small, JAA, FEPlines impacted

Onychomycosis Diagnostic Testing Coverage

Onychomycosis diagnostic testing coverage

Covered when ALL/ANY logic below is met:

ALL of the following

ONE of
- KOH microscopy, fungal culture of desquamated subungual material, or fungal stain of nail clipping(s) may be reimbursed for individuals with onychomycosis.
- For individuals with onychomycosis and for whom antifungal therapy has failed to resolve infection, nucleic acid amplification testing (NAAT) may be reimbursed.
- NAAT may not be reimbursed to screen for, diagnose, or confirm onychomycosis (general use).

Policy Summary

PayerBlue KC

PolicyOnychomycosis Testing Payment Policy

Policy CodePolicy POL-PP-296

Change TypeNo material changes

Effective Date07/01/2025

Next Review Date07/01/2026

Key ActionReimburse KOH microscopy, fungal culture, and fungal stain; reimburse NAAT only after antifungal therapy failure; ATR-FTIR and fungal sterol testing are not reimbursed.

SourceLink

On This Page

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

Laboratory and NAAT Codes

Listed laboratory and NAAT codesCPTCovered

82542	Column chromatography, includes mass spectrometry, non-drug analyte(s)
87101	Culture, fungi (mold or yeast) isolation, with presumptive identification; skin, hair, or nail
87149	Culture, typing; identification by nucleic acid probe, direct probe technique
87150	Culture, typing; identification by nucleic acid probe, amplified probe technique
87153	Culture, typing; identification by nucleic acid sequencing method
87205	Smear, primary source with interpretation; Gram or Giemsa stain
87206	Smear, primary source with interpretation; fluorescent and/or acid fast stain
87220	Tissue examination by KOH slide of samples from skin, hair, or nails for fungi
87480	Infectious agent detection by nucleic acid; Candida species, direct probe
87481	Infectious agent detection by nucleic acid; Candida species, amplified probe

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Reimbursement and Denial Risk Summary

Denial Risk

Reimbursement and Denial Risk Summary

Summary of reimbursement conditions, denial risks, and billing guidance for onychomycosis diagnostic testing. Highlights when NAAT is covered after antifungal failure and which tests are not reimbursed.

Reimbursed tests for onychomycosis: direct microscopic exam with KOH, fungal culture of desquamated subungual material, fungal stain of nail clippings.
NAAT reimbursement: allowed only for individuals with onychomycosis for whom antifungal therapy has failed to resolve the infection (document prior antifungal therapy and failure).
NAAT not reimbursed: for screening, initial diagnosis, or confirmation of onychomycosis absent prior antifungal therapy failure.
Not covered (do not bill): ATR-FTIR spectroscopy for screening/diagnosis/confirmation of onychomycosis, testing for fungal-derived sterols (e.g., ergosterol).
Documentation required: clinical diagnosis of onychomycosis and records showing prior antifungal treatment and inadequate response when submitting NAAT for reimbursement.
Denial risk: claims for NAAT submitted without documentation of prior antifungal failure, or claims for ATR-FTIR or ergosterol testing, will be denied as not medically necessary / not covered.
Billing guidance: use appropriate CPT/HCPCS codes for KOH prep, fungal culture, and fungal staining; submit supporting clinical notes for NAAT claims showing prior therapy and failure.

Key Definitions

NAAT

TermNucleic acid amplification testing (NAAT)

DefinitionLaboratory methods that detect and amplify pathogen nucleic acid (examples include PCR, PCR-RFLP, and next-generation sequencing [NGS]).

Clinical applicationMay be reimbursed for individuals with onychomycosis when antifungal therapy has failed to resolve the infection.

LimitationsNAAT is not reimbursed for routine screening, diagnosis, or confirmation of onychomycosis (general use).

Organisms tested (examples)Includes Candida spp., Aspergillus spp., Trichophyton rubrum, Trichophyton mentagrophytes, Epidermophyton floccossum, Neoscytalidium dimidiatum, Onychocola canadensis, Scopulariopsis spp., Alternaria spp., Acremonium spp., and Fusarium spp.

ATR-FTIR

TermAttenuated total-reflectance fourier transform infrared spectroscopy (ATR-FTIR)

DefinitionA spectroscopic technique (ATR-FTIR) used to analyze sample composition by measuring infrared absorption via attenuated total reflectance.

Coverage stanceATR-FTIR spectroscopy to screen for, diagnose, or confirm onychomycosis does not meet coverage criteria and may not be reimbursed.

Rationale for non‑coverageNot covered due to lack of available published scientific literature confirming the test is required and beneficial for diagnosis and treatment of onychomycosis.