The Smarter Balanced Assessment Consortium (Smarter Balanced) strives to provide every student with a positive and productive assessment experience, generating results that are a fair and accurate estimate of each student's achievement. Further, Smarter Balanced is building on a framework of accessibility for all students, including English Learners (ELs), students with disabilities, and ELs with disabilities, but not limited to those groups. In the process of developing its next-generation assessments to measure students' knowledge and skills as they progress toward college and career readiness, Smarter Balanced recognized that the validity of assessment results depends on each and every student having appropriate universal tools, designated supports, and accommodations when needed based on the constructs being measured by the assessment. This document was developed for the Smarter Balanced members to guide the selection and administration of universal tools, designated supports, and accommodations. This document is divided into several parts: (1) Introduction: This section introduces the document and the conceptual model that is the basis for the universal tools, designated supports, and accommodations in the Guidelines; (2) Section I: This section features the universal tools available on Smarter Balanced assessments; (3) Section II: This section features the designated supports available on Smarter Balanced assessments; (4) Section III: This section features the accommodations available on Smarter Balanced assessments; (5) Appendix A: This appendix provides a summary list of Smarter Balanced's universal tools, designated supports, and accommodations; (6) Appendix B: This appendix describes lessons learned from research on universal design, accessibility tools, and accommodations; (7) Appendix C: This appendix provides Frequently Asked Questions; (8) Appendix D: This appendix provides the Read Aloud Protocol (June 28, 2018); (9) Appendix E: This appendix provides the Scribing Protocol (June 28, 2018); and (10) Appendix F: This appendix provides a Revision Log that lists all changes to this document by section, page, description, date, and version. [Individual sections contain references.]