Energy plays a central role in our society, so it is essential that all citizens understand what energy is and how it moves and changes form. However, research has shown that students of all ages have difficulty understanding these abstract concepts. This paper presents a summary of elementary, middle, and high school students' understanding of elementary school energy ideas. This work is part of a larger project to develop three vertically equated instruments to measure how students make progress in their understanding of the energy concept. The data presented here are from a field test of distractor-driven, multiple-choice items aligned to elementary-level ideas about the forms of energy and energy transfer. These items were tested with students in all three grade bands, even though they explicitly test elementary ideas. A total of 3,037 4th- through 12th-grade students in the U.S. participated, and Rasch modeling was used to analyze the data. Option probability curves were used to represent the distribution of correct answers and misconceptions across the range of student knowledge levels. The shapes of the curves and where they occur as a function of knowledge level suggest that specific misconceptions appear and disappear in sequence as students become more knowledgeable about energy.