Doing the Math With Paraeducators: A Research and Development Project funded by the National Science Foundation, was designed to provide experiences to support professional growth by building paraeducator mathematical knowledge for teaching and leadership in Boston Public Schools. Providing paraeducators with sustained professional learning and opportunities to continue their education can open important pathways to full teaching positions, which has the potential to diversify the teaching pool and address the critical teacher shortage that disproportionately affects high-need urban schools (Walker, 2019). However, paraeducators face barriers that can prevent them from developing as professionals. Many have multiple jobs because of their low salaries, family responsibilities, and limited professional learning or planning time with their teacher colleagues (Butt, 2018; Uitto et al., 2017; Sharma & Salend, 2016). Another major obstacle is that many paraeducators do not see themselves as teachers, as was evident at the first meeting of Doing the Math. By participating in the project, however, the paraeducators made a profound shift in perspective. They began to see themselves as mathematics teachers and even as mentors to their colleagues. With growing confidence, some are now returning to college, others are enrolling in test preparation courses with a goal of taking the state certification exam, and all are assuming greater teaching responsibilities within their classrooms. In these formal and informal ways, they are not only entering the teacher pipeline but strengthening it. What led to this shift? Data, gathered through surveys, observations of professional learning and classroom interactions, and interviews from two cohorts of paraeducators, point to a cycle of experiences that encouraged paraeducator growth. These experiences are described in this article. For each element, the authors offer evidence of the ways in which the program contributed to paraeducator learning and teaching.