CPT code 0561U designates a Proprietary Laboratory Analyses (PLA) test for Haystack MRD™ Monitoring from Quest Diagnostics®, using genomic sequence analysis of whole blood to detect minimal residual disease (MRD) versus a patient’s baseline. As a PLA code tied to a single manufacturer-specific test, 0561U matters nationally because it creates a discrete billing pathway for a specialized molecular assay that informs cancer surveillance and treatment decisions.

Key payers considered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare and Medicare. Readers will find a concise overview of clinical context for MRD testing, an explanation of the PLA designation and implications for coding and claims submission, and a summary of payer coverage patterns where available. The publication also summarizes typical sites of service and the service type to support facility and laboratory billing teams.

This report helps clinicians, laboratory billing staff, and policy analysts quickly understand what CPT code 0561U represents, why it is clinically relevant, and which major payers are part of the national coverage landscape. Data not available in the input will be noted where applicable in later sections of the full publication.