Summary & Overview
CPT 0364U: clonoSEQ® Assay for MRD Monitoring via NGS
CPT code 0364U identifies the clonoSEQ® Assay, a proprietary next-generation sequencing (NGS) test used to detect and monitor minimal residual disease (MRD) in hematolymphoid malignancies via blood or bone marrow specimens. As a PLA code tied to a single manufacturer's assay, it standardizes reporting for a clinically important monitoring tool that can influence treatment decisions and long-term surveillance strategies nationwide. The code matters nationally because MRD status increasingly informs prognosis and therapy selection in hematologic cancers, and clear coding affects coverage, billing consistency, and clinical documentation.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical purpose and service characteristics, payer coverage patterns and benchmarks, applicable billing modifiers and service-line implications, and the clinical context for repeat testing to track disease burden. The publication also summarizes common questions payers consider for NGS-based MRD assays, practical implications for lab and outpatient settings, and where to find additional policy updates. Data not available in the input is noted where relevant.
Billing Code Overview
CPT code 0364U is a Proprietary Laboratory Analyses (PLA) code specific to the clonoSEQ® Assay from Adaptive Biotechnologies. The test uses next-generation sequencing (NGS) to analyze a blood or bone marrow specimen from a hematolymphoid (blood/lymph) cancer patient to identify and track patient-specific clonal DNA sequences associated with the malignancy. Repeated testing enables detection of minimal residual disease (MRD) by measuring persistent or rising levels of these clonal sequences during and after treatment.
Service type: Laboratory — next-generation sequencing-based MRD monitoring
Typical site of service: Clinical laboratory or hospital outpatient laboratory; specimen collection may occur in outpatient clinics or inpatient settings where blood or bone marrow samples are obtained.
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult or pediatric individual diagnosed with a hematolymphoid malignancy (for example, B-cell acute lymphoblastic leukemia, chronic lymphocytic leukemia, multiple myeloma, or other lymphoid neoplasms) undergoing systemic therapy or post-transplant surveillance. The treating hematologist/oncologist orders the 0364U clonoSEQ® Assay to quantify minimal residual disease (MRD) by next-generation sequencing (NGS) of rearranged immunoglobulin or T-cell receptor gene sequences in a peripheral blood or bone marrow specimen. The clinical workflow begins with the clinician documenting the indication in the medical record, obtaining informed consent if required, and ordering the test through the institutional or commercial laboratory ordering portal. A phlebotomy or bone marrow collection is performed at the outpatient clinic, infusion center, hospital inpatient unit, or pathology collection site. The specimen is sent to the manufacturer-designated lab for proprietary processing and NGS analysis. Results reporting includes a quantitative MRD level, interpretation of detectable versus undetectable disease, and comparison with prior clonoSEQ® results to inform response assessment and longitudinal monitoring. Typical use cases include assessing depth of response after induction/consolidation therapy, early detection of molecular relapse during surveillance, and post-hematopoietic cell transplant monitoring.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 |