There's a rise in the employment of uncertified teachers, driven by acute staffing shortages and the flexibility offered by Texas' District of Innovation plans. This reliance on uncertified educators is raising alarms among educators and policymakers alike. Concerns are mounting over whether these teachers, often entering the classroom having never worked in public schools, are equipped to meet the demands of today's classrooms. This brief presents new evidence showing that uncertified teachers are linked to declines in student achievement. The study examines the prevalence, backgrounds, and impacts of uncertified teachers on student achievement and draws attention to significant differences within this diverse group of educators. As schools continue to hire uncertified teachers to address staffing shortages, knowing the backgrounds of these teachers and how they shape student achievement helps stakeholders prioritize transition points, such as hiring individuals with previous classroom experience in non-teaching roles. This brief outlines findings from the 2021-22 and 2022-23 school years and provides recommendations for policymakers and stakeholder groups.