Prior to August 2015, the National Board of Medical Examiners' (NBME) clinical science subject examination scores were reported as a scaled score. However, the scaled scores had some undesirable properties. Medical school faculty often interpreted the scaled scores as though they were percent correct scores despite cautions that this interpretation was inappropriate. Based on feedback from faculty about how they use clinical science subject examination scores and what inferences they want to make about the scores, the NBME decided to change the score scale to better meet the needs of medical school faculty and students. This paper describes the technical and practical considerations associated with the implementation of equated percent correct scores for the clinical science subject examination program.