State boards of education rely on educators and researchers for evidence about the value of approaches in arts education--as in all other disciplines-- to help them weigh needs against the investment and the opportunities for good outcomes for all students and their communities. Yet there is only a modest body of rigorous research to inform education policy decisions related to arts education or arts integration. Two recent evidence reviews by the American Institutes for Research (AIR) examine the impact of the arts in education through the lens of the Every Student Succeeds Act (ESSA), which introduced criteria for evaluating the level of research evidence behind educational programs and practices. Informed by these reviews, the authors find that there are four kinds of gaps with critical implications for state and district decisions related to the arts: (1) gaps in research focus, where there is little or no rigorous research about a particular art type or outcome; (2) gaps regarding size and type of populations participating in a program, such that the results of the research cannot be generalized to other school settings, population locations, or makeup; (3) gaps in recency and reporting, because the timing of the collection of data is not consistent with the scheduled need or the results may not be publicly available; and (4) gaps in understanding the role of mediating factors that affect outcomes, such as location of the program, the student focus, or level of implementation. Research has not kept pace with the stakeholders' needs for policy-relevant information. This article offers the following recommendations for State board members who seek policy-relevant research: (1) Encourage districts to gauge the theoretical and empirical support for arts integration or arts education interventions they wish to adopt; (2) Ask whether and how your state's education department is collaborating with other states to design systems for collecting and sharing data on arts participation and achievement; and (3) Advocate for partnerships between independent organizations and researchers to support more rigorous research and thus stronger evidence for arts integration and arts education.