Background: Despite the increasing number of science, technology, engineering, and mathematics (STEM) jobs available, concern continues to grow over the low number of students who choose to study and enter STEM fields. Research suggests that children begin to identify their interests and career aspirations related to STEM as early as elementary school when they begin to shape their personal identities and start making decisions about who they are and could be in the future, their role identities (e.g., scientist, engineer). Existing surveys that assess identity target high school or post-secondary students, with less work on elementary and middle school students. This paper describes the development and validation of survey instruments to assess engineering identity in elementary students and its adaptation to a more general STEM context. Results: The role identity survey in engineering (RIS-E) was developed across four phases of pilot testing where it was administered to 634 students in third-sixth grade enrolled in classrooms in the West, Midwest, and Northeastern United States. Exploratory modeling approaches and scale reliability were used to narrow down items, while confirmatory factor analyses (CFA) and item response theory (IRT) approaches were used to examine item performance. The final survey contained four scales that assess aspects of one's identity (competence, interest, selfrecognition, and recognition by others), all of which demonstrated strong psychometric properties. The RISE was then adapted to assess STEM identity (RIS-STEM), and it was administered to 678 fourth-fifth grade students enrolled in classrooms in the Southwestern United States. CFA and IRT analyses provided support for use of the RIS-STEM in a more general STEM context. Conclusions: The RISE and RIS-STEM appear to produce reliable scores that measure aspects of identity (engineering and STEM) in elementary students. Suggestions are made for future studies to examine how the RISE and RIS-STEM function across diverse student populations and the impact on one's identity as a result of curricula or programs designed to encourage and support identity development in youth, especially in engineering and STEM.