The recently published National Research Council (NRC) report "A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas" (NRC 2011) offers a thoughtful research-based agenda that helps guide teachers in making the shift to a doing-led agenda in K-12 science education. In the December 2011 editions of the NSTA journals, Rodger Bybee focused on Science and Engineering Practices, Dimension One of the "Framework." Here the focus is on the "Framework's" Crosscutting Concepts--Dimension Two. The "Framework" makes very clear that science learning needs to be coordinated around generative conceptual ideas and scientific practices. The author begins with the seven Crosscutting Concepts, highlighting features within each that reveal the components of progressions. A big challenge for teachers is thinking about planning lessons and units across grade bands as student learning progresses within a grade and across grades. This will require more work, but designing lessons that move students through the Crosscutting Concept progression while teaching the Core Ideas and engaging students in the appropriate Scientific Practices will help ensure that students are doing science in grades K-12. (Contains 1 figure.)