Exclusionary immigration policies impact the day to day lives and transition to adulthood of undocumented immigrants arriving as minors. In response to the challenges faced by these young people, a burgeoning qualitative scholarship has shed light on their experiences. Yet, much of this research has focused on the experiences of children that immigrate at the ages of 12 and under, otherwise known as the 1.5 generation. The plight of the 1.25 generation—those who immigrate between the ages of 13 to 17—has largely been missed. Moreover, the timing of immigration, or the point in the life course when an individual immigrates, has not been considered as a source of differentiation in the experiences of undocumented immigrants. This study examines the experiences and pathways to adulthood of the undocumented 1.25 generation through 40 semi-structured interviews with Mexican and Central American undocumented and DACAmented young adults who immigrated between the ages of 13 to 17. The pathways of the undocumented 1.25 generation diverged into the enrolled and never enrolled based on whether they accessed K-12 schooling in the United States. Gender further demarcated the lives of the never enrolled by structuring their challenges and access to supports. Among the enrolled, their ability to transition and stay on path towards college completion separated them into stayers and leavers. Moreover, the transition to adulthood was differently experienced as a result of their aspirations and the extent that exclusionary immigration laws disrupted the lives they had envisioned. In discussing these findings, I argue that the timing of immigration warrants analytical consideration and that paying attention to the aspirations of undocumented immigrants can provide insight into how exclusionary immigration policies are experienced across the life course. This research provides social workers, educators, and other stakeholders a more complete understanding of the trajectories of undocumented immigrants who arrive as minors. By examining the experiences of the undocumented 1.25 generation, I shed light on the challenges, needs, and vulnerabilities of an understudied population. This knowledge allows for a more nuanced understanding of the plight of undocumented immigrants, and can assist stakeholders to develop more targeted resources, supports, and inclusive policies. This study also advances immigration scholarship by stressing the analytical importance of the timing of immigration and the role of personal aspirations in understanding the lived experiences of undocumented immigrants.