Summary & Overview
CPT 0315U: DecisionDx–SCC Gene Expression Risk Stratification
CPT code 0315U identifies DecisionDx®–SCC, a proprietary RT–PCR gene expression profiling test for squamous cell carcinoma (SCC) that classifies metastatic risk into Class 1 (low), Class 2A (moderate), and Class 2B (high). As a PLA code tied to a single manufacturer's assay, 0315U is used when FFPE tissue from an SCC lesion is analyzed in a clinical laboratory setting. Nationally, PLA codes like 0315U matter because they link clinical decision tools directly to unique commercial tests, affecting coding clarity, claims processing, and policy decisions for molecular diagnostics.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise orientation to the clinical application of the test, typical sites of service, payer coverage landscape, and the types of benchmarks and policy issues that commonly arise with PLA molecular diagnostics. The publication summarizes coverage considerations, common billing modifiers, and operational notes relevant to laboratories and billing professionals. Data not supplied in the input—such as specific payer policy details, associated taxonomies, ICD‑10 diagnoses mapping, and related codes—is noted as unavailable and therefore not included in the analysis.
Billing Code Overview
CPT code 0315U is a Proprietary Laboratory Analyses (PLA) code for DecisionDx®–SCC, a genomic test manufactured by Castle Biosciences, Inc. The assay uses formalin–fixed paraffin–embedded (FFPE) tissue from a skin lesion diagnosed as squamous cell carcinoma (SCC) and applies reverse–transcription polymerase chain reaction (RT–PCR) gene expression profiling to measure activity of 40 genes (34 content genes and 6 housekeeping genes). An algorithmic analysis of the gene expression data stratifies metastatic risk into Class 1 (low risk), Class 2A (moderate risk), and Class 2B (high risk).
Service type: Proprietary laboratory molecular diagnostic test (gene expression profiling)
Typical site of service: Clinical laboratory or hospital outpatient laboratory using FFPE tissue specimens
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult who presents to a dermatology clinic with a biopsy-confirmed cutaneous squamous cell carcinoma (SCC). The surgical dermatologist or dermatopathologist prepares formalin-fixed paraffin-embedded (FFPE) tissue from the diagnostic biopsy or from the excision specimen and submits the block or unstained slides to Castle Biosciences, Inc. for DecisionDx®–SCC testing. The test uses reverse-transcription polymerase chain reaction (RT–PCR) to measure expression of 34 content genes and 6 housekeeping genes and reports a risk category for metastasis as Class 1 (low risk), Class 2A (moderate risk), or Class 2B (high risk).
Typical clinical workflow: the treating clinician documents the SCC diagnosis and rationale for molecular prognostic testing (for example, high-risk tumor features or uncertainty about management). The pathology laboratory prepares and ships the FFPE material with required documentation and billing information. The laboratory or ordering clinician reports the DecisionDx–SCC result to the treating provider; the result informs risk stratification and multidisciplinary management discussions (surveillance intensity, imaging, adjuvant therapy consideration, or surgical margins). Billing uses PLA code 0315U for the proprietary Castle Biosciences assay, with appropriate specimen and service site indicated (commonly outpatient dermatology clinic, hospital outpatient department, or independent pathology lab).
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 |