Utilizing Social Cognitive Career Theory (SCCT), we investigated the importance of identity-based factors such as personal inputs and contextual affordances (e.g., having children, being married or employed, school-family conflict, stress, participating in Native American cultural activities) in understanding Native American undergraduates' intentions and decision to major in STEM fields. Past studies have examined the role of SCCT in undergraduate students' major choice and the underrepresentation of certain marginalized groups in STEM majors. Yet few studies have examined if these relationships extend to Native American undergraduates or how the SCCT model may vary based on the complex identities Native American peoples may hold. The findings highlight the importance of contextualizing major choice through a Native American lens. For Native American students, we find being married or employed, having children, and family stress negatively impact intent to major in STEM fields. We also find support for several SCCT variables and intent to major in STEM disciplines. Specifically, we discuss fostering identity as a scientist as a fruitful avenue for increasing intent to major in STEM fields. Results are compared to a White undergraduate group and implications are discussed for institutions of higher education and Tribal governments and leaders.