Standardized cognitive and educational assessments of individuals with intellectual disability (ID) provide crucial information for parents, researchers, and educators. Understanding the unique developmental strengths and challenges of an individual with ID is imperative to determining appropriate educational placements, developing intervention plans, and measuring growth. However, challenges associated with ID in areas such as communication, attention, and self-regulation can interfere with the validity of test results and lead to students being labeled "untestable." Unfortunately, there is a paucity of research regarding administrative procedures that yield valid standardized assessment results with this population. This paper outlines best practices in standardized assessment accommodations based on a literature review, professional standards, legal precedence, and extensive field research. A model for assessment will be proposed, consisting of an iterative four-stage cycle of planning, administration, evaluation, and reporting. Practical ideas for accommodations will inform school psychologists so they can obtain valid and useful scores when administering standardized assessments with students with ID.