We suggest a method to automatically evaluate employees' subject matter expertise in knowledge management systems. The approach stems from several conclusions that arose in extensive research of subject matter experts and their expertise. We find that self-reported expertise is biased and constantly changing. We, furthermore, observe that automatic methods to infer expertise perform about as well as self-reported profiles. The crux of the proposed method is to combine automatic inference expertise with the benefit of the expert's opinion, and to do so periodically so the profile remains accurate and fresh. 13 PagesExternal Posting Date: December 6, 2012 [Fulltext].Approved for External PublicationInternal Posting Date: December 6, 2012 [Fulltext]