It is acknowledged that English language learners (ELL) perform lower than their non-ELL peers and that their lack of language acquisition impacts their graduation rates. However, the approaches taken to reduce the achievement gap between ELL and non-ELL students varies widely. To maximize ELL graduation rates, content area and ELL teachers need to purposefully collaborate on lesson formation using a structured protocol to guide their planning through a meaningful and targeted approach. This mixed-methods case study leverages two key strategies to develop the areas mentioned above, including increasing ELL English language acquisition and engagement, as well as establishing ELL and content area teacher collaboration through the use of structured common planning time. The theory of action in this study proposes that if structured, common planning time is made available for the content area teacher and the ELL teacher, who focuses on academic English language, an increase in ELL student academic achievement and graduation rates will be achieved. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]