Community colleges are frequently an affordable, accessible entrance to a Science, Technology, Engineering, and Mathematics (STEM) education and career, but the transition from a 2-year program to a 4-year institution can be tumultuous. In this mixed-methods study, we explore the experiences of transfer and prospective transfer students. Through surveys and interviews, we identify the challenges faced by and the supports desired by biology transfer students. We describe how community college students perceive their introductory biology courses, and we compare the biology identity and self-efficacy of these students to peers at a 4-year institution. Students expressed uncertainty about what to expect from the transfer experience, and they benefitted from interventions that made the university experience more concrete or clarified their expectations. We found that community college students are just as interested in biology as peers at a 4-year university, but they are significantly less likely to believe that others recognize them as "biology people" and report less self-efficacy regarding biology courses. Students felt particularly well-prepared for transfer after community college biology courses they described as "rigorous" and "demanding," especially because students expressed that the community college environment helped support them through the challenges of higher education.