This study explored the enactment of formative assessment practices in 89 observed lessons across 15 middle and high school science teachers before and after they participated in workshops that coalesced around formative assessment, teaching science to English learners (ELs), and integrating Next Generation Science Standards with Common Core Literacy Standards. An observation rubric developed from the literature on formative assessment and teaching ELs in the context of science education looked at 7 assessment practices organized around 3 dimensions: assessment design, assessment use, and language/literacy considerations. Findings articulate distinct implementation levels across the assessment practices. Moreover, findings reveal 2 prototypical lesson types that did not fully reflect more responsive approaches to teaching ELs. Articulating commonly observed assessment practices could help refine research and instructional tools to support science teachers and teacher educators as they consider formative assessment through new perspectives.