Abstract Background Warm autoantibodies (WAAs) cause delays and additional expenses while determining suitable products when using a traditional protocol (TP). In 2013, Carter BloodCare Immunohematology Reference Laboratory (IRL) introduced a molecular protocol (MP) for patients with WAAs. Study Design and Methods Retrospective review of records for samples referred to the IRL from November 2004 to September 2020, was performed. Referrals, alloantibody(ies), gender, and age were recorded.