With school populations across the country becoming increasingly representative of students from diverse cultural and linguistic backgrounds, new considerations must be made to promote equitable and engaged science learning for all students (National Academy of Science, National Academy of Engineering, & Institute of Medicine [NAEEM], 2011). The Next Generation Science Standards (NGSS) respond to a need for equity by explicitly calling on science teachers to “acquire effective strategies to include all students regardless of racial, ethnic, cultural, linguistic, socioeconomic, and gender backgrounds” (NGSS Lead States, 2013, Appendix D, p. 38). Some prior research has criticized the NGSS for simply being another set of standards that constrain what it means to know and do the discipline, and thus, do not allow for diverse ways of knowing that do not align with the standards (Rodriguez, 2013; Miller et al., 2018). As such, there needs to be greater understanding about what effective strategies teachers use to teach diverse learners within the context of a reform-oriented science education landscape that calls for actively engaging students in science practices (Ko & Krist, 2019). The overarching goal of this dissertation is to examine one such strategy, specifically how middle school science teachers in California provide opportunities for epistemic agency by drawing on students’ funds of knowledge. Epistemic agency is a construct which helps us to understand inequity in science education (Carlone et al., 2015). By attending to who has more or less power to direct the intellectual work of the classroom, we come to see patterns in who is afforded more or less power. One approach to attending to issues of power in the classroom and respecting children, their intelligence, and the communities they come from is to utilize a funds of knowledge perspective (Moll et al., 1992). A funds of knowledge approach to teaching and learning encourages teachers to draw on the cultural and community knowledges that students bring from outside of the classroom (e.g., home and family) to counteract deficit perspectives of diverse student populations. This mixed-methods study seeks to understand how teachers both draw on students’ funds of knowledge and enact their epistemic agency in the context of NGSS-aligned instruction. Participants included grades 6-8 science teachers across California, some who participated in targeted, extensive professional learning about the NGSS and some who received little training. The study was conducted in Fall 2018 through the end of Spring 2020. Data were collected and analyzed using qualitative and quantitative methods that included teacher and student survey data, classroom observations, and teacher interviews. Overall, there were increases in teachers’ reported average implementation for epistemic agency and funds of knowledge across study years. However, while teachers reported increased enactment of epistemic agency over study years, students reported that the source of the questions and investigations in their class was more often derived from a source external to them (like a textbook, worksheet, or other material that was given by the teacher) rather than being derived from the students themselves or from their communities. Findings reinforce prior literature that question the NGSS as a set of standards that suggests students be the “do-ers” of science, so long as they are doing the science that is outlined in the standards (Berland et al., 2019; Lowell et al., 2020; Miller et al., 2018). Students’ ideas and questions were not frequently the basis of investigations in class and enactment of epistemic agency only went so far as eliciting student ideas that are recognizably aligned to the standards.