81403

Molecular Pathology, Tier 2 (Specified Genetic Analysis)

CPT code 81403 is designated for molecular pathology procedures involving genetic analysis (quantitative and qualitative, including characterization) that do not have a more specific CPT code (Tier 1). It represents a specific level of complexity or analysis scope within the Tier 2 series, often used for targeted sequencing of genes, deletion/duplication analysis, or other molecular assays for specific genes or genomic regions, to diagnose, prognose, or guide treatment for various genetic and neoplastic conditions.

Clinical Indications

  • Diagnosis or confirmation of rare genetic disorders with an identified genetic basis (e.g., specific forms of muscular dystrophy, mitochondrial disorders, complex metabolic diseases).
  • Identification of specific somatic or germline mutations, gene fusions, or copy number variations in neoplastic conditions for targeted therapy selection, prognosis, or minimal residual disease monitoring when not covered by Tier 1 codes.
  • Carrier screening for specific genetic conditions when comprehensive sequencing or analysis of specific gene regions is required.
  • Genetic risk assessment for hereditary conditions in symptomatic individuals or at-risk family members (e.g., certain hereditary cancer syndromes beyond standard panels).
  • Investigation of unexplained developmental delays, intellectual disability, or congenital anomalies when a specific gene etiology is suspected.

Procedure Steps

  1. Patient consultation and informed consent, including genetic counseling if appropriate.
  2. Collection of biological specimen (e.g., blood, saliva, tissue biopsy).
  3. Extraction and purification of DNA or RNA from the collected specimen.
  4. Performance of molecular assay (e.g., next-generation sequencing, Sanger sequencing, quantitative PCR, multiplex ligation-dependent probe amplification (MLPA), array comparative genomic hybridization) targeting the specific gene(s) or genomic regions of interest.
  5. Bioinformatic analysis and interpretation of raw data, including variant calling and classification.
  6. Correlation of molecular findings with clinical phenotype by a molecular pathologist or geneticist.
  7. Generation of a comprehensive clinical report detailing methods, findings, interpretation, and recommendations.

Coding Guidelines

  • This code is to be used only when no specific Tier 1 CPT code is available for the molecular test performed.
  • The medical record documentation must clearly specify the exact gene(s) analyzed, the specific genomic regions or mutations tested, and the methodology employed.
  • Medical necessity for the specific, unlisted molecular test must be fully documented, including clinical indications and how the results will impact patient management.
  • Tier 2 codes are typically reported once per test/gene analyzed, regardless of the number of assays performed on the same specimen for the same gene.
  • Do not unbundle components of a single molecular test; report the most appropriate Tier 2 code that encompasses the entire service.
  • The specific Tier 2 code (e.g., 81401-81408) is chosen based on the level of complexity, often determined by factors such as the number of exons, base pairs, or the technical effort involved, as defined by the AMA for Tier 2 services.

Associated ICD-10 Codes