This article reports on an Elementary and Secondary School Counseling Program (ESSCP) grant project designed to build an elementary school counseling program in a district that previously had not employed school counselors at that level. The new school counseling program was organized around an innovative shift in the district's multi-tiered system of supports (MTSS) model that expanded to integrate social-emotional and behavioral data with academic indicators. School counselors used the new social-emotional data to help answer the question of why students were struggling academically when scholastic deficiencies were not the primary cause. The grant project also focused on developing strong data literacy skills among elementary school counselors so they could serve as leaders in data-based discussions. These complementary grant goals transformed the data team process as school counselors, teachers and administrators began to use data to better understand the complex relationship between social-emotional factors and academic achievement. These practices resulted in systemic changes throughout the district as data-driven elements of the elementary school counseling program were adopted at the secondary level. The purpose of this article is to: (a) highlight the importance of engaging in data-based decision making regarding students' social-emotional needs in schools, (b) provide an overview of the specific elements that comprised the new MTSS model in the school district as a part of this grant-funded project, and (c) underscore the importance of building human capacity to enable school-based data teams to meaningfully integrate academic and social-emotional data to promote improved student outcomes. Limitations of this project, directions for future research and implications for school counselors also are discussed.School Counselors and Social-Emotional DataSchool counselors are often advised to adopt a data-based decision-making model as part of their practice (American School Counselor Association [ASCA], 2012; Dimmitt, Carey, & Hatch, 2007). Accountability mandates require school counselors to use data to demonstrate the impact of their work and to link their interventions to academic achievement (Dahir & Stone, 2009: Isaacs, 2003; Sink & Stroh, 2003.) Moreover, data use also is central to the transformed model of school counseling, which positions school counselors as advocates in educational reform efforts such as closing the achievement gap and carrying out school improvement initiatives (Dahir, 2004; Hayes, Nelson, Tabin, Pearson, & Worthy, 2002; House & Hayes, 2002). However, institutional factors can limit the role of the school counselor in data-based decision making. Typically, data teams primarily (or even exclusively) consider academic indicators, and schools often lack the infrastructure to systematically collect the social-emotional data that more directly aligns with the work of the school counselor.Accountability requirements of the No Child Left Behind Act of 2001 (NCLB; 2002) have strongly influenced schools' approaches to data-based decision making (Mandinach, Honey, & Light, 2006; Marsh, Pane, & Hamilton, 2006). The pressure to demonstrate adequate yearly progress (AYP) has prioritized state standardized tests scores and other academic benchmark assessments in data-driven discussions. A tremendous amount of achievement data were routinely collected and housed by school districts to fulfill reporting demands of NCLB; these data will continue to be gathered under the new Every Student Succeeds Act (ESSA; 2015). School staff can access these data to guide instructional practices and measure student progress. However, these data are more directly linked to teachers' work with students and primarily measure academic achievement and cognitive ability (Heckman & Rubinstein, 2001).The role of the school counselor encompasses not only students' academic achievement but also their social-emotional development (ASCA, 2012). …