The issue of parallel forms is of paramount importance for producers of standardized tests. With increasing emphasis being placed on standardized test results it is necessary that each student achieve the same standard score regardless of the form he or she was administered. In the case of the American College Testing (ACT) Assessment Program, five different forms are administered annually. Each form is purported to be measuring the same skills with the same degree of accuracy. The parallelism of two forms of the Mathematics Usage Test from the Enhanced ACT Assessment Program (EAAP) that were administered to 2,500 examinees during the fall of the 1989-90 academic year was examined. Unlike traditional studies of parallelism, this study illustrated several new techniques that can be used to study parallelism from a multidimensional item response theory (MIRT) perspective. Based on the MIRT analysis, the tests did not appear to be multidimensionally parallel, although conditions that could alter this conclusion are discussed. Recognizing the fact that most tests assess multiple abilities, it is proposed that the methodology can provide a basis for future research. Nine tables and eight figures, as well as an appendix that illustrates two test items, are included. (Author/SLD)