Anti-CD38 is used to treat relapsed or treatment-refractory multiple myeloma. CD38 monoclonal antibodies, however, can interfere with routine blood bank serologic tests. Agglutination is observed at the indirect phase of testing as the drug binds to red blood cells (RBCs). Resolving the testing interference causes delays issuing RBC units to patients with anemia. A number of devised methods to eliminate or bypass the effects of anti-CD38 on serologic tests are in use but no panacea exists. The limitations of each method require each testing site tailor an approach to best fit their needs. We present perspectives and testing practices from a hospital transfusion medicine service and an Immunohematology Reference Laboratory managing pretransfusion samples with anti-CD38.