Summary & Overview
CPT 81364: HBB Gene Full Sequence Analysis
CPT code 81364 represents full-gene sequencing of the hemoglobin, beta subunit (HBB) gene, a molecular diagnostic test used to identify variants associated with hemoglobinopathies such as sickle cell disease and beta-thalassemia. Nationally, accurate classification of HBB variants supports diagnostic confirmation, carrier screening, and clinical management decisions, making this code relevant for genetic laboratories, clinicians, and payers managing genetic testing coverage.
Key payers considered include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context for HBB sequencing, typical sites of service, and a summary of common reimbursement and coding factors relevant to laboratories and billing teams. The publication highlights benchmarking metrics where available, summarizes recent policy themes affecting molecular sequencing claims, and outlines coding considerations tied to the technical sequencing service. Data not available in the input for specific payor policies, utilization rates, and associated ICD-10 diagnoses are noted where applicable.
Billing Code Overview
CPT code 81364 describes a laboratory genetic test in which the technical laboratory component analyzes the entire gene sequence of the hemoglobin, subunit beta (HBB) gene. The service type is molecular genetic testing / full gene sequencing. Typical site of service is a clinical diagnostic laboratory or reference lab that performs high-complexity molecular testing.
Clinical & Coding Specifications
Clinical Context
A 3-year-old child of Mediterranean descent with a family history of beta-thalassemia and recent microcytic anemia presents to a pediatric hematology clinic. The treating team orders comprehensive molecular testing of the hemoglobin, subunit beta gene to determine the presence of pathogenic variants causing beta-thalassemia or other HBB-related hemoglobinopathies. A peripheral blood specimen is collected in EDTA and sent to a molecular diagnostics laboratory. The laboratory performs DNA extraction, full-gene sequencing of HBB (including exon, intron, promoter, and commonly interrogated regulatory regions), variant calling, and interpretive review by a clinical laboratory scientist and molecular pathologist. Results describing identified sequence variants, classification (pathogenic/likely pathogenic/variant of uncertain significance/benign), zygosity, and clinical interpretation are returned to the ordering clinician, who integrates the findings with hemoglobin electrophoresis and clinical presentation for diagnostic confirmation, genetic counseling, and family cascade testing when indicated.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional interpretation component separate from the technical laboratory processing if applicable. |