Background: Repeated calls to diversify the population of students earning undergraduate degrees in science, technology, engineering, and mathematics (STEM) fields have noted the greater diversity of community college students and their potential to thus have an impact on the racial/ethnic composition of 4-year degree earners. In this paper, we investigate barriers and supports to Black women's success in STEM, using longitudinal interview data with seven Black women who were enrolled at community colleges and stated an interest in majoring in STEM at 4-year institutions. Results: Our findings highlight a contrast between community colleges and universities. At community colleges, Black women were able to form supportive relationships with professors and peers, downplayed the potential of racism and sexism to derail their STEM ambitions, and saw little to no impact of bias on their educational experiences. Those students who transferred characterized university climates very differently, as they struggled to form supportive relationships and experienced racism and sexism from professors and peers. Conclusions: We conclude using Patricia Hill Collins' Domains of Power framework to categorize students' experiences, then end with recommendations for change that will result in less alienating experiences for Black women, among other minoritized students.