CPT code 81105 represents a molecular diagnostic laboratory test that determines the genotype of the two common alleles of Human Platelet Antigen 1 (HPA–1), also referenced as CD61 or ITGB3. This platelet antigen genotyping assay has clinical implications for transfusion compatibility, platelet refractoriness evaluation, and prenatal assessment of alloimmune platelet disorders. Nationally, such targeted genetic testing supports precision transfusion management and maternal-fetal risk assessment.

Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication provides a concise overview of coverage and billing practice trends across major national payers and Medicare, with attention to clinical context and coding implications.

Readers will find a clear description of the clinical purpose and typical service settings for CPT code 81105, an outline of common modifiers associated with laboratory services, and guidance on what benchmark and policy items are covered in the full publication. The document clarifies where data are available and flags areas where input did not supply specific payer policy details. This summary is intended to orient laboratory billing staff, clinical geneticists, and policy analysts to the code's clinical role and the scope of the accompanying analysis.