CPT® Code 86900

The CPT® Code 86900 refers to the procedure of blood typing, specifically focusing on the serologic determination of the ABO blood group system. This procedure involves analyzing a blood specimen to identify the blood type, which can be one of four categories: type A, type B, type AB, or type O. The process begins by mixing the blood sample with specific antibodies that target type A and type B blood. The reaction is observed for agglutination, which is the clumping of blood cells. This clumping indicates the presence of corresponding antigens on the surface of the red blood cells. For instance, type A blood contains anti-B antibodies and will agglutinate when exposed to type B antibodies, while type B blood contains anti-A antibodies and will agglutinate in the presence of type A antibodies. Type O blood, which has antibodies against both A and B, will agglutinate when mixed with either type A or type B antibodies. Conversely, type AB blood does not have anti-A or anti-B antibodies and will not agglutinate when mixed with either type of antibody. Following the initial typing, a back-typing process is performed, where the blood serum is mixed with known type A or type B blood to confirm the blood type. This comprehensive testing is crucial for safe blood transfusions, organ transplants, and various medical procedures where blood compatibility is essential.