Background Competency‐based education (CBE) is a systems‐change approach intended to re‐shape traditional understandings of what, when, where, and how students learn and demonstrate academic knowledge and skills. Research on the factors that affect K‐12 CBE implementation and the efficacy of different approaches has not yet been meticulously reviewed. Aims The purpose of this literature review was to examine the research on K‐12 CBE for factors that affect implementation, student outcomes, and the relationship between implementation and student outcomes. Methods A systematic literature review was conducted that included 25 peer‐reviewed studies and unpublished reports from 2000 to 2019 related to K‐12 students. Results Facilitators and barriers that affect K‐12 CBE implementation were fairly consistent across studies. Factors perceived as barriers in some contexts were viewed as facilitators in others—it all depended on stage of implementation. Findings about the outcomes of CBE for K‐12 students reflected mixed results with respect to claims that CBE implementation supports (a) academic achievement and progress; (b) intrinsic motivation and engagement; and (c) other important academic outcomes. Discussion Undergirding all findings in this review is the difficulty of isolating the research on implementation and outcomes of K‐12 CBE approaches in some “pure form.” It may make more sense for the field to coalesce around a common continuum of practices in relation to the key elements of CBE from more traditional models to more competency‐based models. Also, assessment as a key feature of CB implementation was absent from most of the studies reviewed which is notable given that determining competence is fundamentally an assessment decision. Directions for future research are discussed. Conclusion For many, the promise of CBE and related practices is that student achievement will improve and minimize equity gaps. This systematic review serves to amplify what is known about CBE approaches and what still needs investigation.

Background and Context T he federal peer review process was established as a means of evaluating the academic standards and assessments developed or selected by a state to ensure they meet the requirements of the Elementary and Secondary Education Act (ESEA) of 1965. Under the 2015 reauthorization of ESEA known as the Every Student Succeeds Act (ESSA), required assessments include general and alternate assessments in Mathematics and Reading/language arts annually in each of grades 3-8 and at least once in the grade span of 10-12; Science in each grade span 3-5, 6-8, and 10-12; and English Language Proficiency for grades K-12. With the exception of science, the results from these assessments are a required element of a state's school accountability system and used to inform decisions about which schools are excelling or in need of support. The use of assessment results to inform school accountability relies on an assumption that the test design appropriately represents the content and cognitive emphasis reflected in the state's academic standards. If this assumption does not hold, the scores will not provide for valid inferences regarding the degree to which students have met these expectations and schools and educators will be held accountable for content that differs from those standards. Other potential negative consequences include: r a shift or narrowing of instruction to reflect the focus of the assessment; r student frustration and lack of motivation (i.e., for being tested on material that does not reflect what they are taught); and r loss of faith by stakeholders that the assessment provides accurate information about student achievement and growth and the accountability system provides valid information about which schools are in need of support. The current peer review guidance requires states to provide substantial evidence that a state's assessment system addresses the depth and breadth of its academic standards and demonstrate an appropriate range of cognitive complexity. Per the guidance, assessing the breadth and depth of the standards means that each state assessment covers the "domains or major components within a content area" and that "specific content is not specifically excluded from a state's assessment system" when evaluated over a period of time (U.S.