Using grounded theory, we examined the ways in which undergraduate teacher candidates with disabilities developed a sense of purpose and constructed professional identities. Our findings suggest K-12 experiences with advocacy as well as exclusionary school experiences influenced their emerging professional identities. Resistance to a deficit view of disability was central to teachers' professional identities and influenced their desire to become "change agents" in their future professions. We describe collegiate experiences that affirmed or presented roadblocks to their career path.