Given the growing evidence of limited attention to science, disciplinary literacy, and oral language in elementary classrooms serving low-income children, this study focused on designing and testing an integrated science and disciplinary language and literacy curriculum aligned with NGSS and CCSS ELA standards for kindergarten. We used design-based implementation research (DBIR) to create curriculum materials to support children's science talk and conducted a quasi-experimental study to examine children's (N = 147) oral language outcomes. Kindergartners receiving the curriculum outperformed children in business-as-usual kindergarten classrooms in their ability to make claims, give evidence-based supports, knowledge of receptive science vocabulary, and use of vocabulary in a science context. Findings indicate that with appropriate scaffolding and support, kindergartners can engage in sophisticated science talk and that integrated curriculum materials can impact young children's science learning and science discourse.