This article advocates the use of a decision-making flowchart to help understand whether the proposed test alteration(s) is an accommodation or a modification. If the proposed alteration is not listed in state guidelines, the flowchart directs the IEP team to identify (a) the purpose of the test and (b) the consequences of the scores so that the team is specifying the parameters of any validity arguments. Next, the IEP team must decide whether the proposed setting, presentation, or response alteration (a) changes the measured construct(s), (b) is based upon need versus benefit, (c) produces differential outcomes for various groups or individuals, and (d) generates different judgments. Finally, utilizing empirical outcomes the team decides whether the proposed alteration more closely resembles an accommodation or a modification. Research reviews regarding setting, presentation, and response alterations are also presented that may provide IEP teams with some empirical guidance.The 1997 amendments to the Individuals with Disabilities Education Act (IDEA '97) affirmed the rights of students with disabilities to participate in large-scale testing. The more recent No Child Left Behind (NCLB) legislation also ordered the participation of students with disabilities in statewide assessments.