The federal No Child Left Behind Act of 2001 ("NCLB" or "the Act") defines an aggressive, ambitious and multi-faceted approach for increasing student achievement and closing the achievement gap. Premised on the correlation between student academic achievement and teacher quality, NCLB demands that all students, regardless of race, ethnicity, disability or income, have quality instructors in their classrooms. To do so, NCLB establishes mandatory credentialing standards for teachers and paraprofessionals, in both traditional and charter schools alike. This Policy Brief explains NCLB's credentialing requirements and applicability to teachers and paraprofessionals working in charter schools (Part I) and examines authorizer responsibilities for ensuring compliance with these requirements in the charter schools they oversee (Part II). It includes a Model Checklist for Monitoring Compliance with NCLB Credentialing Requirements. (Contains 9 resources and 7 endnotes.)