The current "K-12 Science Education framework" and "Next Generation Science Standards" (NGSS) in the United States emphasise the integration of engineering design in science instruction to promote scientific literacy and engineering design skills among students. As such, many engineering education programmes have developed curriculum materials that are being used in K-12 settings. However, little is known about the nature and extent to which engineering design skills outlined in NGSS are addressed in these K-12 engineering education programme curriculum materials. We analysed nine K-12 engineering education programmes for the nature and extent of engineering design skills coverage. Results show that developing possible solutions and actual designing of prototypes were the highly covered engineering design skills; specification of clear goals, criteria, and constraints received medium coverage; defining and identifying an engineering problem; optimising the design solution; and demonstrating how a prototype works, and making iterations to improve designs were lowly covered. These trends were similar across grade levels and across discipline-specific curriculum materials. These results have implications on engineering design-integrated science teaching and learning in K-12 settings.