This study examines the stability of the "SAT Reasoning Test"™ score scales from 2005 to 2010. A 2005 old form (OF) was administered along with a 2010 new form (NF). A new conversion for OF was derived through direct equipercentile equating. A comparison of the newly derived and the original OF conversions showed that Critical Reading and Mathematics score scales have experienced, at most, a moderate upward scale drift (no greater than 5 points on average), and the drift may be explained by an accumulation of random equating errors. The Writing score scale has experienced a significant upward scale drift (11 points on average), which may be caused by sources other than random equating errors.