Exploratory and confirmatory factor analyses of domestic data from the" GRE"® revised General Test, introduced in 2011, were conducted separately for the verbal (VBL) and quantitative (QNT) reasoning measures to evaluate the unidimensionality and local independence assumptions required by item response theory (IRT). Results based on data from the period immediately after the launch of the revised test and data from a year later showed that very little local item dependence was present and that a predominant single factor accounted for each of the data sets. These results provide evidence supporting the assumptions that underlie the use of the unidimensional 2-parameter IRT model for scoring and contribute evidence for the validity of GRE scores and their use.