(How) can individuals bring about adaptive changes in their development themselves? Building on the action-phase model (Heckhausen, 1999) a 4-wave longitudinal study was conducted to investigate agency and adaptation in the transition from university to work. The sample consisted of 523 university graduates from four selected fields of study with favorable vs. unfavorable employment opportunities. Semi-structured interviews were conducted with 15 participants one year after graduation. Findings from latent growth curve modeling showed that individuals changed indeed after graduation and that individual agency predicted the direction of these changes. Specific motivational orientations (i.e., learning goals, goal self-concordance) predicted adaptive goal engagement, which in turn predicted subjective and psychological well-being as well as selected aspects of work adaptation. Most findings generalized across favorable vs. unfavorable employment contexts. The results are discussed referring to different theoretical frameworks, highlighting points of convergence with the qualitative findings and considering potential applications.