N. S. Raju, W. J. van der Linden, and P. F. Fleer (in press) have proposed an item response theory-based, parametric procedure for the detection of differential item functioning (DIF)/differential test functioning (DTF) known as differential functioning of item and test (DFIT). DFIT can be used with dichotomous, polytomous, or multidimensional data. This study describes and provides a simulated demonstration of the polytomous-DFIT framework. Factors manipulated in the simulation were: (1) length of test (20 and 40 items); (2) focal group distribution; (3) number of DIF items; (4) direction of DIF; and (5) type of DIF. The DFIT framework was effective in identifying DTF and DIF in polytomously scored data for the conditions simulated. The preliminary findings provide promising results and indicate directions for future research. (Contains 3 figures, 6 tables, and 21 references.) (Author/SLD)