Multiple factors go into making an effective professional development (PD) program for K-12 teachers. Focusing on content, active learning, collaboration and coaching support and using models of effective teaching can broaden the knowledge of science teachers. However, many teachers are short on the resources needed to attend one-time short-term PD programs. Additionally, there is little data on the effect of national PD programs on student achievement. The results of one online PD program for teachers will be shared today as part of American Physiological Society’s (APS’s) Institute on Teaching and Learning in Madison, Wis.