Making is an iterative process of designing, building, tinkering, and problem-solving, resulting in the creation of personally meaningful artifacts. Fueled by recent developments in affordable, safe, and easy to use digital fabrication technologies, making has been embraced by educators the world over. While educational scholarship is developing an increasingly complex understanding of the practices and pedagogies needed to support making in the classroom, there has been limited research associated with the preparation of teachers and their development of maker-centered instructional practices. In this embedded case study, the authors examined artifacts produced by 13 secondary preservice and in-service science, technology, engineering, or mathematics (STEM) classroom teachers engaged in long-term maker professional development as part of a microcredentialing program. Analysis of these artifacts uncovered an array of motivations for engaging with classroom making, illustrated how participants implemented their maker philosophies in secondary STEM classrooms, and suggested the need for additional research on and models of maker-centered programs in teacher preparation.