Deciding whether to grant test accommodations for a student with disabilities is challenging and controversial. Current accommodations practice is seldom research based, and professionals charged with such decisions often reach different conclusions. The result can be either unnecessary accommodations that compromise test validity or the denial of accommodations to a student who needs them. In this book, Benjamin Lovett and Lawrence Lewandowski draw on research to offer clear, specific guidelines for deciding when accommodations are appropriate for a student with disabilities -- depending on the test being taken, the accommodations being considered, and the student's functional skills. Case studies apply the guidelines to specific scenarios. The book also explains how laws and practices differ for K-12 accommodations versus postsecondary education and workplace accommodations, as well as how universal test design might lessen the need for test accommodations.