This study examines motivational factors of teachers who have achieved a national standard of professionalization. Data were collected from National Board certified teachers in the United States (N = 453) using a two-part, web-based survey. Exploratory factor analysis found five motivators: improved teaching, financial gain, collaborative opportunities, self and external validation. Analyses of Variance (ANOVAs) highlighted differences in the financial gain and external validation motivations, depending on the teacher's age at the time of certification. The results of this study reveal multiple motivators for teacher professionalization, with teachers of different ages motivated by diverse incentives. (Contains 4 tables.)