Percentiles are not provided in connection with USMLE scores. The calculation and provision of data to be used to rank or make comparisons among examinees is inconsistent with the primary goal of USMLE, which is to provide a series of assessments and recommendations for minimum passing requirements to the state licensing authorities to support decisions about initial licensure. Furthermore, normative data such as percentiles are easily misinterpreted because, as the examinee group changes across time, the correspondence between percentile values and examinee ability can change. For these reasons, USMLE does not report percentiles.
Under current procedures, the scores for each administration of a USMLE Step are equated so that a given 3-digit score represents essentially the same level of examinee performance for that Step, and this holds true across years. In other words, a score of 200 on one administration of a Step indicates a comparable level of examinee performance as a score of 200 on any other administration of the same Step. This equivalence holds even if the pass-fail standard is changed, which permits comparing performance across time.
It is important also to remember that the 2-digit score, also reported for USMLE, is not a percentile and is not fully equated like the 3-digit score. The 2-digit score is a total test score that is designed to meet the requirements of some state licensing authorities. The 2-digit score scale is one on which a 75 is always the minimum passing score. A given 2-digit score may represent a different level of performance if the two administrations were subject to different pass/fail standards.