CPT code 81110 denotes a molecular diagnostic genotyping test that identifies the two common alleles of Human Platelet Antigen 6 (HPA–6), also called R489Q, using specimens such as blood or amniotic fluid. The code captures the technical laboratory component of allele analysis performed by a laboratory analyst. Nationally, molecular platelet antigen testing is important for managing alloimmune platelet disorders, prenatal risk assessment, and transfusion compatibility testing.

Key payers included in the analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of clinical context for HPA–6 genotyping, typical sites of service where testing is performed, and the scope of billing activity tied to CPT code 81110. The publication outlines common billing modifiers and service-line considerations when available, notes typical laboratory workflows, and summarizes how this specific genotyping code fits into broader molecular diagnostics and transfusion medicine practice.

This summary is written for a national audience and aims to provide clinicians, billing professionals, and policy analysts with clear context on what CPT code 81110 represents, why HPA–6 testing matters clinically, and what elements are generally considered when this service is billed.