This study investigates the association between involvement with sustained professional development (PD) and students' physics learning for teachers engaging with the Physics through Evidence, Empowerment through Reasoning (PEER) curricular suite. PEER supports high school teachers attempting to align their instruction with the Next Generation Science Standards (NGSS) through collaborative engagement with curricular materials, sustained PD, and three-dimensional assessments. Using data collected from 21 teachers and employing hierarchical linear modeling, we examine whether variation in PD participation is predictive of students' gains on a conceptual examination of physics learning. Findings indicate that attending a PEER PD session was associated with a 1.46% positive difference in average gain scores, when controlling for teacher characteristics. PD attendance also explained 49.48% of between-teacher variation in conceptual gains. These results emphasize the efficacy of sustained PD for increasing student learning in NGSS-aligned courses.