Given current high-stakes uses of tests, one of the most pressing and difficult problems confronting the field of measurement is to develop better methods for distinguishing between meaningful gains in performance and score inflation. This study explores the potential usefulness of adapting differential item functioning (DIF) techniques for this purpose. It distinguishes between reactive and nonreactive changes in DIF over time and relates these to the framework for validating scores under high-stakes conditions offered by Koretz, McCaffrey, and Hamilton (2001). It contrasts score-anchored and item-anchored approaches to DIF in terms of their potential for this purpose. It explored changes in the distribution of DIF in the NAEP eighth-grade mathematics assessment between 1990 and 2000 in five low-gain and five high-gain states, in each case treating all other participating states as the reference group. It used the score-anchored method of DIF analysis implemented in BILOG-MG (Bock & Zimowski, 2003b), which allows only item difficulties to vary across groups. This exploration indicated that the approach has potential but confronts several substantial difficulties. Further exploration using data from high-stakes testing programs is recommended.