Elementary school teachers struggle to collect and use reading progress data to make instructional decisions. Collecting and interpreting reading progress data when making instructional decisions allows districts to identify and support students who need early reading intervention and may protect districts from Free Appropriate Public Education violations. The purpose of this study was to describe the reported practices of teachers for systematically collecting and using student reading progress data and to identify areas where additional support and training in these practices are necessary. Teacher reported practices were described using a conceptual framework based on the data-based decision making (DBDM) heuristic published by Kearns et al. (2021). The steps of DBDM were aligned with the steps of the Response to Intervention process and placed within Ajzen's (1991) theory of planned behavior. This qualitative, single-case study consisted of two groups of participants: (1) nine general education teachers; and (2) six special education teachers. Using purposeful sampling, teachers were recruited via a paper flier placed in their mailboxes and direct email. Research questions were crafted to provide answers about professional development activities, attitudes and beliefs, and assessment and instructional decision-making practices. Using NVivo, a total of 16 themes were identified and revealed that teachers believe data informs instruction, use a variety of assessments, and teachers report difficulties in systematically collecting and using student reading progress data to make instructional decisions. The implications for practice are that the district should provide: (1) additional structure regarding assessment practices; (2) additional training regarding data interpretation; and (3) guidance or structure regarding interventions. Recommendations for future research include using a school site protocol to assess the transfer of district policies into practice at the school sites, expand participants to include administrators and school psychologists, and include an observation protocol. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]