The purpose of this study is to determine if there is a difference in the English language acquisition of first grade students in transitional bilingual programs as compared to students in dual language programs during the 2017-2018 academic year. The Assessing Comprehension and Communication in English State-to-State (ACCESS) standardized assessment was used to compare the reading, writing, speaking, listening, and overall language acquisition composite of English language learners in two programs at the first-grade level. The ACCESS composite and performance scale scores in each of the four domains were used to compare the English language proficiency of students in first grade. A multiple linear regression was applied to test the effects on the English language acquisition of first grade students in dual language and transitional bilingual classes, while controlling for other factors that could also have a potential effect. The control variables in the regression model were socioeconomic status (SES), level of language proficiency in kindergarten, and student gender. The findings indicated the type of program was only associated with first-grade performance in writing, with students in transitional bilingual programs performing better than their peers in dual language programs. No association was found between the type of program and first-grade performance in reading, listening, speaking, or overall English language acquisition composite. This study was limited to students within one school district and analyzed a small sample size of students in transitional bilingual and dual language classes. The findings are specific to students at the first-grade level and does not extend to upper grade levels, where research demonstrates students in dual language programs outperform their peers in other bilingual program models. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]