There is a mountain of evidence demonstrating that students with marginalized, i.e. purposefully socially excluded, identities experience significantly worse academic and social outcomes in STEM disciplines. However, there has been less attention on how white women, who experience sexism due to their gender but are privileged due to their race, simultaneously contribute to and play a role in dismantling systemic racism. In this study, I used constructivist grounded theory to explore the process through which white women in STEM commit to racial justice both within and outside of their disciplines. Interviews with 36 white women in STEM across a range of disciplines helped build an emergent model that illustrated how participants advanced through three stages to move toward actionable anti-racist commitment. However, many participants struggled to connect STEM with their anti-racist practice, as many STEM disciplines lacked anti-racism curriculum and/or the ability to practice anti-racism within STEM. This model helps illustrate the complex process in which white women in STEM become committed to racial justice. Within STEM specifically, this research has direct implications for the importance of adding social contexts and anti-racist material directly into STEM curricula to foster anti-racist practices for future STEM professionals.