The Next Generation Science Standards (NGSS) provide a vision for contemporary science education with all students, including the fast-growing population of multilingual learners in the United States K-12 context. The shifts heralded by the NGSS have resulted in significant changes to English language proficiency (ELP) or English language development (ELD) standards so they better align with content standards and support all students, including multilingual learners, to engage in language-rich disciplinary practices (e.g., arguing from evidence). The purpose of this article is to describe ELP/ELD standards aligned with content standards. Specifically, we describe how the policy initiatives of the NGSS as science standards and WIDA 2020 as ELP/ELD standards reflect each other in terms of conceptual foundations and architecture of the standards guiding classroom practices. By becoming more explicitly aware of how science standards and language standards present "mirror images" of each other, science educators will be better positioned to collaborate with their language education colleagues. As this article is intended to engage science educators who are generally familiar with the NGSS but likely new to ELP/ELD standards, we describe WIDA 2020 in detail and in ways accessible to a broad audience. In doing so, we aim to ensure the science education and language education communities are coordinated in their efforts to promote equitable science learning for all students, including multilingual learners. We close with implications for research, policy, and practice through collaboration between science education (as well as other content areas) and language education.