The Houston Independent School District offers two different English as a Second Language (ESL) programs for students whose native language is not English and who need to develop and enhance their English language skills (English Language Learners, or ELLs). The Content-Based ESL model (CB-ESL) consists of an intensive program of English instruction in all subject areas with instruction delivered through the use of ESL methodology, commensurate with the student's level of English proficiency. The district also offers a Pullout ESL model (PO-ESL), where students are served with an ESL language program for part of each day but are in a mainstream instructional setting in other subject areas. The purpose of this report is to provide program staff with a detailed examination of ELLs enrolled in the district's two ESL programs. Included in the report are findings from assessments of academic achievement and English language proficiency, including results from the English State of Texas Assessments of Academic Readiness (STAAR), the STAAR End-of-Course (EOC), and the Texas English Language Proficiency Assessment System (TELPAS). Performance data from 2015-2016 appears to show that students in the CB-ESL program performed slightly better than those in the PO-ESL program across some assessments (STAAR reading and mathematics, TELPAS progress), while PO-ESL performed better than CB-ESL on other assessments (TELPAS proficiency, STAAR EOC English I and II). Results for exited ESL students showed students from both programs did well relative to the district, indicating that ESL students were capable of closing the performance gap relative to the district, with exited CB-ESL doing somewhat better than exited PO-ESL students.