CPT code 0309U designates a Proprietary Laboratory Analyses (PLA) test specific to Prevencio Inc.'s HART CVE®, which measures four plasma proteins and applies an algorithm to produce a risk score for major adverse cardiovascular events, including myocardial infarction and stroke. Nationally, PLA codes like 0309U matter because they identify single-source diagnostics with unique clinical utility that can influence patient management and payer coverage decisions. Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find succinct benchmarks and clinical context for the test, a summary of payer coverage considerations, and notes on typical sites of service and service classification. The publication highlights how the test is reported in claims using CPT code 0309U, describes its intended clinical application—cardiovascular risk stratification from a plasma sample—and outlines where the service is typically performed (clinical laboratory with outpatient specimen collection). Data not available in the input is noted where applicable. This overview equips payers, providers, and policy analysts with the information needed to interpret the code's purpose, potential impact on care pathways, and the landscape of payer engagement at a national level.