Demands placed on early childhood teacher development, teacher candidates, and professionals who prepare future teachers, continue to increase. Although inquiry addresses high-stakes teacher development, research on programs in early childhood professional development schools as a pathway to mediate the increased demand is needed. The purpose of this study is to develop a framework to evaluate teacher candidate development that is aligned with state measures of teacher effectiveness in a professional development school. Constructivist grounded theory (Charmaz, Constructing grounded theory, Sage, 2014) guided the collection and analysis of forty-three semi-structured interviews. A theoretical framework of three interrelated categories was identified: Engaged Teacher Candidate, Professional Teacher Candidate, and Reflective Teacher Candidate. Even further, seven interrelated sub-categories in the teacher candidates' development were identified: establish relationships, classroom management, technical aspects of teaching, teacher quality standards, professional dispositions, self-reflection, and goal setting. The overarching framework was named Proficient Teacher Candidate. The framework will be evaluated against a taxonomy of development in relation to a professional development school.