This report is an update of the assessment principles and guidelines for English language learners published in 2013 (Thurlow, Liu, Ward, & Christensen). That report, which was developed by the Improving the Validity of Assessment Results for English Language Learners with Disabilities (IVARED) project, presented essential principles of inclusive and valid assessments for English learners with disabilities. Since the publication of that report, the educational context has changed. This update of the report recognizes the contextual changes, but does not alter the principles themselves. This report presents five core principles of valid assessments for English learners with disabilities, along with a brief rationale and specific guidelines that reflect each principle. The principles are: (1) Content standards are the same for all students; (2) Test and item development include a focus on access to the content, free from bias, without changing the construct being measured; (3) Assessment participation decisions are made on an individual student basis by an informed Individualized Educational Program (IEP) team; (4) Accommodations for both English language proficiency (ELP) and content assessments are assigned by an IEP team knowledgeable about the individual student's needs; and (5) Reporting formats and content support different uses of large-scale assessment data for different audiences. Appendices included in this report describe the Delphi data collection process, and members of the expert panel. References and selected core resources related to each principle and guideline are also included in an appendix. [For the 2013 report, "Assessment Principles and Guidelines for ELLs with Disabilities," see ED609832.]