Postdoctoral scholars constitute a sizeable population within the academic workforce. Given the intended role of a postdoc position as a time of advanced training and professional development for a future academic career, particularly in science, technology, engineering, and math (STEM) fields, it is important to understand whether and how well the career-related needs of postdocs are being met. The purpose of this research was to understand STEM postdoctoral scholars’ career trajectories, with particular attention to the influences on their career-related decision making, by applying the Life Experiences and Role Negotiations (LEARN) model to qualitative data from interviews with 19 STEM postdocs. Findings reveal the multiple influences on postdocs’ career-related decisions and how these shape postdocs’ career trajectories. Based on our findings, we offer three suggestions for how institutional and national policies and programs can best support the career development of postdocs.