A new generation of science curriculum materials is being developed and made widely available across K-12. These materials, along with their associated professional learning, are expected to play a pivotal role in transforming science instruction to meet the vision of A Framework for K-12 Science Education and the performance expectations of the Next Generation Science Standards. This study investigated one of the first widely available middle school curriculum programs designed for the NGSS, Amplify Science 6-8. The study team conducted a randomized experiment to examine the implementation and efficacy of the middle school curriculum program (materials plus teacher professional learning) for improving seventh grade students' learning in physical science. Findings show that students in schools where the program was implemented significantly outperformed peers in the comparison condition on an NGSS-focused physical science assessment. These findings underscore the importance of conducting additional research on NGSS-designed curriculum programs across other grade levels and within different science domains.