Using nationally representative High School Longitudinal Study of 2009 data, this quantitative study examined how math teacher qualifications affect U. S. 9th graders’ math achievement and attitudes. The study is guided by the Cognitive Apprenticeship Theory that emphasizes that expert teachers enable students to learn as apprentices and construct knowledge within the activity, context, and culture in which it is learned. The study shows that not only does cognitive apprenticeship enable skill development and knowledge acquisition, but it shapes student math self-efficacy and interest in the subject, and it develops their math identity if students viewed math teachers as role models. The study employs a comparative research design to explore the main effects and interaction between teachers’ credential type and field of study degree on student outcomes. One notable finding is that teacher credentials (i.e., level of education certification) affected student math achievement and math identity but had weaker effects on math self-efficacy, math utility and interest in math courses. Second, holding a math degree affected students’ math achievement and math identity, while holding a degree in education had some positive effects on increasing students’ interest in math courses. Results have direct implications for the field of Mathematics Education showing that teacher qualifications affect student beliefs and attitudes toward mathematics.