CPT code 0249U represents a Proprietary Laboratory Analyses (PLA) code for the Theralink® Reverse Phase Protein Array (RPPA) assay, a laboratory-developed test that quantifies and assesses activation of 32 phosphoproteins and cell-surface receptor proteins in breast tumor tissue and delivers an algorithmic interpretive report. As a PLA code tied to a single manufacturer's assay, 0249U signals a specific, high-complexity molecular diagnostic service with potential impact on targeted therapy selection and precision oncology workflows nationally. Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will learn what CPT code 0249U denotes clinically and operationally, how payers approach coverage and billing for proprietary molecular assays, and the clinical context in which RPPA-based reports may inform treatment decisions. The publication summarizes typical sites of service and service type, lists common modifier usage where applicable, and points to the PLA nature of the code for contract and prior authorization considerations. Data not available in the input for associated taxonomies, ICD-10 diagnoses, related codes, and service-line level detail are noted where relevant.