CPT® Code 90371

The CPT® Code 90371 refers to Hepatitis B immune globulin (HBIg), which is a human-derived immunizing agent administered via intramuscular injection. This product is a concentrated solution containing antibodies specifically designed to provide short-term, passive immunity against the hepatitis B virus. Unlike active immunization, where the recipient's immune system is stimulated to produce its own antibodies, HBIg offers immediate protection without triggering the body's immune response to generate additional antibodies. The antibodies present in HBIg are sourced from the pooled blood of multiple donors who have previously developed immunity to hepatitis B, ensuring a robust supply of protective antibodies. This code is specifically used to report the administration of human hepatitis B immune globulin for intramuscular use, focusing solely on the product itself rather than any associated procedures or services.