CPT code 81375 represents a laboratory test for low- or intermediate-resolution molecular typing of human leukocyte antigen (HLA) Class II loci, including HLA–DRB1/3/4/5 and HLA–DQB1. This code identifies the technical component of molecular HLA testing used in transplant compatibility assessment, immunogenetics research, and certain diagnostic contexts where class II HLA determination is clinically relevant. Nationally, HLA typing remains critical for organ and stem cell transplantation programs and for select autoimmune disease evaluations, making accurate coding important for clinical workflows and payer reimbursement.

Key payers referenced in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context, typical sites of service, and the types of insights commonly included in billing-code publications: utilization benchmarks, coding guidance and common modifiers, and relevant policy or coverage considerations. Where specific payer policy details or taxonomies are not available in the input, the summary notes that data is not available.

This publication provides clinicians, billing staff, and policy analysts with a clear description of what CPT code 81375 covers, where the service is typically performed, and what to expect in terms of the content areas usually reviewed when evaluating HLA molecular testing codes.