CPT code 86817 designates a laboratory serologic test to identify multiple human leukocyte antigens (HLA) from HLA Class II antigens, specifically the DR and DQ loci. This test is clinically important for organ and tissue transplant compatibility assessment, immunogenetics research, and certain autoimmune disease evaluations. Nationally, standardized reporting of HLA testing supports transplant allocation, cross-match interpretation, and clinical decision-making across diverse health systems.

Key payers included in this overview are Aetna, Blue Cross Blue Shield, Cigna, UnitedHealthcare, and Medicare. Coverage policies and reimbursement for HLA serologic testing vary by payer and clinical indication; payers often reference medical necessity criteria tied to transplantation, graft-versus-host disease evaluation, or specific diagnostic questions.

Readers will learn the clinical scope of CPT code 86817, the typical laboratory setting where the service is performed, and the primary reasons the test matters in clinical pathways. The publication summarizes benchmark considerations, common billing modifiers associated with laboratory services (listed separately), and the broader policy context affecting access and payment. Data not provided in the input—such as payer-specific rates, precise coverage rules, associated taxonomies, and ICD-10 mappings—is identified as unavailable. The content is presented to inform coding, billing workflows, and policy review at a national level.