Although early studies of executive functioning in children supported Miyake et al.'s (2000) three‐factor model, more recent findings supported a variety of undifferentiated or two‐factor structures. Using a cohort‐sequential design, this study examined whether there were age‐related differences in the structure of executive functioning among 6‐ to 15‐year‐olds (N = 688). Children were tested annually on tasks designed to measure updating and working memory, inhibition, and switch efficiency. There was substantial task‐based variation in developmental patterns on the various tasks. Confirmatory factor analyses and tests for longitudinal factorial invariance showed that data from the 5‐ to 13‐year‐olds conformed to a two‐factor structure. For the 15‐year‐olds, a well‐separated three‐factor structure was found.