Purpose: As maker-centered learning grows rapidly in school environments, there is an urgent need for new forms of assessment. The purpose of this paper is to report on the development and implementation of tools to support embedded assessment of maker competencies within school-based maker programs and describes alternative assessment approaches to rubrics and portfolios. Design/methodology/approach: This study used a design-based research (DBR) method, with researchers collaborating with US middle school teachers to iteratively design a set of tools that support implementation of embedded assessment. Based on teacher and student interviews, classroom observations, journal notes and post-implementation interviews, the authors report on the final phase of DBR, highlighting how teachers can implement embedded assessment in maker classrooms as well as the challenges that teachers face with assessment. Findings: This study showed that embedded assessment can be implemented in a variety of ways, and that flexible and adaptable assessment tools can play a crucial role in supporting teachers in this process. Additionally, though teachers expressed a strong desire for student involvement in the assessment process, we observed minimal student agency during implementation. Further study is needed to investigate how establishing classroom culture and norms around assessment may enable students to fully participate in assessment processes. Originality/value: Due to the dynamic and collaborative nature of maker-centered learning, teachers may find it difficult to provide on-the-fly feedback. By employing an embedded assessment approach, this study explored a new form of assessment that is flexible and adaptable, allowing teachers to formally plan ahead while also adjusting in the moment.