CPT code 90378 represents intramuscular respiratory syncytial virus immune globulin (RSV–IgIM), a human hyperimmune immunoglobulin preparation used to provide passive immunity against RSV. This biologic product is clinically important for protecting high-risk infants and other vulnerable populations from severe RSV infection and is billed separately when administered intramuscularly. National attention on 90378 stems from its role in preventive care for at-risk patients and the billing considerations associated with specialty biologics.

Key payers covered in this overview include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a compact review of the code’s clinical context and common sites of service, plus guidance on the types of benchmarks and policy issues typically relevant to this code: coverage policies, medical necessity criteria, and billing practices for intramuscular immune globulin products. Where specific payer policy details or comparative benchmarks are required, those items are identified as areas for further lookup, since beneficiary eligibility, prior authorization requirements, and coverage criteria can vary across payers.

This summary serves clinicians, billing staff, and policy analysts who need a clear characterization of CPT code 90378, its clinical purpose, and the payer landscape to inform billing, coding, and coverage inquiries at a national level.