Better understanding of how students achieve vertical transfer is vital for advancing equity in science, technology, engineering and mathematics (STEM) majors. Among the many sources of barriers, delays, and complexities demonstrated in previous research as influencing vertical transfer outcomes, the transfer admission process has been generally neglected. Using a longitudinal, qualitative design, and drawing on transfer capital and field theories, this study investigated how community college students who are underrepresented in STEM fields successfully navigated admission to a four-year institution in a STEM major. Results indicated that students experienced transfer admission as risky and uncertain. They accrued transfer capital over time, in the form of knowledge about transfer admission and strategies to bolster their competitiveness, including regulating their coursework intensity and actively managing their GPAs. Although these forms of transfer capital helped students succeed in transferring, some strategies could backfire, causing unintended negative consequences, such as time-to-completion delays, excess credit accumulation, or disadvantages in securing admission. Results supported the contention that the transfer admission process is a pivotal, yet largely neglected aspect of student experience in STEM vertical pathways. Conclusions provide suggestions for further research and implications for institutional practice.