Universal design for assessments is an approach to educational assessment based on principles of accessibility for a wide variety of end users. Elements of universal design include inclusive test population; precisely defined constructs; accessible, non-biased items; tests that are amenable to accommodations; simple, clear and intuitive instructions and procedures; maximum readability and comprehensibility; and maximum legibility. The purpose of this guide is to provide states with strategies for designing tests from the very beginning, through conceptualization and item construction, field-testing, item reviews, statewide operationalization, and evaluation. The objective is to create tests that present an accurate measure of the knowledge and skills of the diverse population of students enrolled in today's public schools. This guide is accompanied by an online supplement, which can be accessed at www.nceo.info/UDmanual/.