This study explores the motivations for becoming a teacher, teachers' self-efficacy, and the relationship among motivations and teacher self-efficacy using data from the TALIS 2018. The data included responses from 1933 United States teachers with six or more years of teaching experience. Results indicate that motivations, which were more intrinsic and altruistic, for becoming a teacher are positively correlated to teacher self-efficacy of classroom management, instruction, student engagement, and multicultural classrooms. The largest relationship was between motivation and self-efficacy in multicultural classrooms; the smallest relationship was between motivation and self-efficacy of classroom management. Extrinsic motivations had limited relationships to self-efficacy.