Ensuring that students are reading proficiently by third grade is a key component of keeping students on track to graduate high school and pursue college and careers. Because of the magnitude of this academic milestone, states typically pursue policies that promote early identification and intervention for struggling readers. However, teachers are the most important school-based factor in student success. To ensure that teachers are well-prepared to guide students toward meeting the critical milestone of reading proficiency by third grade, states have begun to require that teacher candidates pass a reading instruction-specific assessment prior to licensure. These assessments address the science of reading instruction and target early childhood and elementary teacher candidates. States are expanding policies that hold teachers and teacher-preparation programs accountable for student success. Requiring rigorous, content-specific assessments prior to licensure is part of a broader trend of holding teachers to higher standards, requiring greater transparency in teacher-preparation programs and modernizing the teaching profession. Fourteen states require teacher candidates to demonstrate knowledge of the science of reading instruction on a stand-alone assessment prior to licensure. Six states use a state or as-yet unspecified test (California, Mississippi, New Mexico, Ohio, Oklahoma, Virginia). Five states use the Foundations of Reading test (Connecticut, Massachusetts, New Hampshire, North Carolina, Wisconsin). Three states use the Praxis Teaching Reading test (Alabama, Tennessee, West Virginia).