The purpose of this chapter is to review what has happened, and what is likely to happen, as accessibility and accommodations research and practice for content assessments are advanced to ensure the appropriate inclusion and validity of assessment results for English learners (ELs) and students with disabilities. A description of accommodations and research specific to access for these two populations is beyond the scope and can be found in other chapters. Although the authors focus primarily on large-scale content assessments used at the state, consortia, and national levels, much of what has happened in these assessments has direct implications for district content assessments and classroom-based assessments (e.g., online embedded tasks, publisher quizzes, teacher-developed quizzes, observational tools, performance tasks, etc.). Thus, they highlight some of those implications as well. The authors address in some depth accessibility and accommodations considerations for students with disabilities, starting from foundational assumptions, then moving to research findings and needs, and concluding with implications for district and classroom assessments. Following this, they address these same topics for ELs, and then for ELs with disabilities.