In this study, the authors propose and test a model of professional identity development among early career student affairs professionals. Using survey data from 173 new professionals (0-5 years of experience), factor analysis revealed 3 dimensions of professional identity: commitment, values congruence, and intellectual investment. Multivariate analyses found significant associations of age, master's program characteristics, and influential people and experiences (e.g., interactions with professional colleagues and associations) with the dimensions of professional identity. Findings indicated key socialization experiences during and after graduate school were associated with the development of professional identity. The authors conclude with recommendations for practice and research.