English language learners (ELLs) in K-12 schools continue to increase in number across the country. In California alone, about 1.5 million students are not sufficiently proficient in English to perform optimally in mainstream classrooms. The No Child Left Behind (NCLB) Act of 2001 emphasizes the need for highly qualified teachers, but just who is qualified to apply best educational practices to help ELLs reach their potential in an academic environment? This article will discuss how the Teachers of English to Speakers of Other Languages (TESOL)/National Council on the Accreditation of Teacher Education (NCATE) P-12 ESL teacher-preparation standards provide a nationally recognized framework for teacher preparation and evaluation, while at the same time providing for flexibility in the way in which certified ESOL teachers are prepared. Graduates of programs that follow these standards are ready to begin meeting the challenges of educating the next generation of ELLs in American classrooms.