Census-based estimates suggest that at least 3.5 million children in the United States are limited-English-proficient or non-English-speaking. Half of all U.S. teachers have one or more of these children in their classes, but only one in 17 has any specific training to teaching English as a second language (ESL). Of those actually teaching ESL classes, most have little or no specialized training. ESL instruction requires unique background and skills, and ESL teacher certification is needed to legitimize and institutionalize the field as licensure has in other specialized fields. Recommended ESL teacher education program elements include academic specialization (study of language in general and the systems of English, language learning processes, and language in culture), instructional methodology and assessment, teaching experience, and the learning of another language's linguistic structure and culture. At least 26 states and the District of Columbia have established certification or endorsement of ESL teachers, but not all of those states require teacher qualification in all of those program areas. (MSE)