Assessment of student ability is often clouded by the interaction between content knowledge and prerequisite access skills. These ancillary skills can influence the students’ level of engagement with the test material by limiting their ability to access the test information or respond to the questions. In the case of mathematics, for example, reading and writing are viewed as access skills in that a student is required to be proficient in these skills in order to succeed on the multiple choice mathematics items (Helwig, Rozek-Tedesco, Tindal, Heath, & Almond, 1999). Students with deficiencies in these access skills are unable to demonstrate their knowledge and skills in the construct under investigation by the test (Elliott, Kratochwill, & McKevitt, 2001). To compensate for these access barriers, test accommodations are provided that change the manner in which the test items are delivered, the setting in which the test is taken, the timing of the test, and/or the administration procedures employed during testing. In a traditional paper and pencil test, these changes to the test are only possible by retrofitting existing materials. In an online computerized testing platform, however, accommodations can be embedded within the design and delivery of the items, thereby creating a seamless testing environment that integrates the necessary support structures to provide all students with an equal opportunity to succeed. The purpose of this chapter is to highlight the process we used to create an accommodated mathematics test for third grade students in an online environment.