Through its Geoscience Teacher Training (GEO-Teach) program, the Directorate for Geosciences (GEO) at the National Science Foundation (NSF) will support projects designed to improve the quality of geoscience instruction, primarily at middle and high school levels. GEO-Teach projects will give teachers access to curricular materials and will implement pre-service teacher training and in-service professional development programs designed to enhance middle and high school students’ understanding of and appreciation for the importance of the geosciences. GEO-Teach projects should emphasize the importance of an Earth system science approach in geoscience education and should promote the integration of content drawn from atmospheric science, Earth science, and ocean science disciplines. The relevance of the geosciences to modern society should be made clear by GEO-Teach products and activities. GEO-Teach projects should take a leadership role in the geoscience education community by providing services and support to that community.