As the United States attempts to address inequities in student outcomes by evolving equitable education for all students in the 21st century, the Multi-Tiered System of Support (MTSS) framework has been promulgated to support educators at all levels of the PK-12 system in continuous observation, learning, and development of public education systems in equitably fostering student growth. The purpose of the study was to explore the data practices utilized by a Southern California local education agency (LEA) and a constituent school site, which has received outside technical assistance for its MTSS implementation in at least one domain of the framework. Specifically, the focus was centered on the application of data to support the systems and structures so all students can access growth. The study will reveal the groundwork of progress and the complexities of MTSS data practices. The study aimed to describe how the district and the school site conceptualized their data-driven decision-making practices, through their beliefs, values, and goals. A qualitative case study design was implemented, allowing data to be grounded and contextualized by the work that data teams in the district and the school site were doing in relation to MTSS data practices. Interviews, observations, and artifacts were collected from both district and site-level educators. The study's findings indicate that the participating district and school site were at the beginning phases of aligning their practices as they shifted toward a shared collectivist mentality throughout all system work, focused on making their "all students can learn" mantra a reality. While the many educators within the district were working to align data-driven decision-making systems, conflicting values complicated the effort. Specifically, the paradoxical district values of individual agency (to do what each educator thought was best) and fidelity (to common processes and systems) made it difficult for the district to align its data practices, while innovation in the middle of a conservative political climate made it difficult to navigate the diverse needs in the community the district served. Furthermore, the efforts to create aligned data-driven decision-making systems left out key elements, including (a) the step of creating actionable knowledge by asking deep, critical questions related to the origins of observed inequities, (b) the step of evaluating the impact of interventions for students who experienced them, (c) ensuring that the systems extended beyond students at the Tier 3 level of intervention to include all students in the other two tiers as well, and (d) incorporating student engagement in the process (i.e., students actively being involved in developing their own learner identity and goals for growth). Due to these missing elements, data practices were more overall performative in nature rather than transformative. The findings indicated that MTSS data practices require leadership of the system and within the system. This can support a continuous and intentional examination of the system work and can provide intentionality to learn about and engage the community and students that the districts serve. Work toward equity is always "in progress," and no matter where they are currently, districts and schools should use data-based decision making with a critical lens to strive for continuous improvement. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]