This article identifies a number of issues associated with current STEM education reform efforts, especially with regard to efforts to integrate engineering education into the K-12 curriculum. Precollege engineering is especially problematic in STEM reform since there is no well-established tradition of engineering in the K-12 curriculum. This discussion aims at identifying some of the issues and problems that serve to impede implementation of engineering education in the K-12 environment. Historically, engineering education has been the purview of higher education, and the epistemology of engineering education has not evolved to specifically inform the exigencies of K-12 education. There also is little in the way of cohesive standards that establish appropriate precollege engineering knowledge and skills and to provide a framework for shared understandings, cooperative partnerships across institutional boundaries, curricular development and implementation, and teacher preparation and professional development. The lack of standards and an epistemic foundation and tradition in K-12 engineering results in significant gaps in experience and knowledge to inform implementation, which is proceeding in schools despite these glaring obstacles--driven by legislative mandate, STEM funding initiatives, workforce demand, and other compelling forces. The lack of systemic infrastructure and support mechanisms for preengineering--such as are found in the sciences, mathematics, and other academic disciplines already participating in K-12 education--have resulted in a situation in which there is no clear, generally agreed upon standards and definition of a body of engineering knowledge, skills, and activities that constitute appropriate curricular content for teaching and learning in K-12 education.