Summary & Overview
CPT 81306: NUDT15 Variant Detection, Targeted Genotyping
CPT code 81306 identifies a molecular diagnostic assay that detects common variants in the NUDT15 gene (alleles *2, *3, *4, *5, *6). This test is clinically significant because NUDT15 variants are associated with altered metabolism of thiopurine medications, affecting dosing, toxicity risk, and treatment planning across oncology, gastroenterology, and rheumatology. Nationally, genetic tests like CPT code 81306 are increasingly integrated into precision medicine workflows and pre-therapy screening protocols.
Key payers included in this review are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical purpose of the test, the typical service setting (clinical or hospital laboratory), and common billing considerations. The publication also outlines benchmarking topics and policy-relevant areas readers can expect to explore, including reimbursement benchmarks, coverage policies, and coding guidance where available. Data not available in the input is noted where applicable. This summary equips clinicians, lab administrators, and billing professionals with the essential context to interpret CPT code 81306 in national practice and payer environments.
Billing Code Overview
CPT code 81306 describes a laboratory test performed to detect specific genetic variants in the nudix hydrolase 15 gene (NUDT15). The service targets commonly observed NUDT15 alleles such as *2, *3, *4, *5, and *6 to identify genetic changes that can affect drug metabolism.
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Service type: Clinical molecular diagnostic assay (genetic variant detection)
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Typical site of service: Clinical laboratory or molecular diagnostics laboratory (ambulatory laboratory setting or hospital-based laboratory)
Data not available in the input for associated taxonomies, ICD-10 diagnoses, and related codes.
Clinical & Coding Specifications
Clinical Context
A patient of Asian descent with inflammatory bowel disease (Crohn disease or ulcerative colitis) is scheduled to start thiopurine therapy (azathioprine or 6-mercaptopurine) or requires dose adjustment after adverse effects. The clinician orders targeted NUDT15 genotype testing to detect common loss-of-function alleles (*2, *3, *4, *5, *6) that increase risk of thiopurine-induced myelosuppression. A peripheral blood sample or buccal swab is collected in the outpatient clinic or phlebotomy lab and sent to the molecular diagnostics laboratory. The lab analyst performs the technical assay for 81306 and reports variant calls and interpretive notes to the ordering gastroenterologist or primary care provider. Results are documented in the electronic health record and used to guide initial dosing, alternative therapy selection, or safety monitoring plans. Typical sites of service include outpatient clinics, hospital outpatient phlebotomy centers, and reference molecular diagnostic laboratories.
Coding Specifications
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