Abstract Introduction/Objective UC Davis Medical Center (UCDMC) is the Sacramento region’s only level 1 adult and pediatric trauma center. It serves a 65,000 square mile area that includes 6 million residents from 33 counties across Northern and Central California. Nearly 7000 patients are transfused annually at UCDMC. Blood supply restrictions, especially on group O negative red blood cells (RBCs), escalated by the COVID-19 pandemic, posed significant patient safety risk. We sought to mitigate this risk by employing restrictive O negative RBC transfusions as recommended by AABB Choosing Wisely, through ABO matched small volume transfusions in neonate and pediatric patients. Methods/Case Report We conducted monthly audits starting in January 2021 to identify trends in O negative RBC use at UCDMC. We partnered with our blood supplier, American Red Cross (ARC), to modify hospital blood inventory. In 2022, we implemented the RBC aliquoting procedure using AS-3 RBCs to facilitate ABO matched small volume transfusions in neonates and children to conserve O negative blood supply. We reviewed regulatory standards, developed standard operating procedures, performed extensive technical validations, and worked with IT to enhance laboratory information system for product manufacturing, labeling, and traceability. We developed education documents for physicians, other providers, nurses, and transfusion services staff including sustainable competency and training. We conducted audits post implementation to measure goal performance in Q4 of FY22, compared to pre- implementation baseline data from Q1 of FY22. Results (if a Case Study enter NA) N/A Conclusion We achieved 57% reduction in O negative RBC utilization post implementation of the RBC aliquoting procedure in Q4 of FY22. Overall O negative RBC use trend at UCDMC improved with a 58% reduction between January 2021 to December 2022. Subsequent reduction of orders was achieved.We conclude that ABO matched RBC aliquot transfusion in neonates and pediatrics is an effective laboratory practice to reduce O negative RBC usage.