Labour market, health, and wellbeing research provide evidence of increasing educational inequality as individuals age, representing a pattern consistent with the mechanism of cumulative (dis)advantage. However, individual life courses are embedded in cohort contexts that might alter life course differentiation processes. Thus, this study analyses cohort variations in education-specific life course patterns of subjective wellbeing (i.e. life, health and income satisfaction). Drawing upon prior work and theoretical considerations from life course theories, this study expects to find increasing educational life course inequality in younger cohorts. The empirical analysis relies on German Socio-Economic Panel data (1984–2016, v33). The results obtained from cohort-averaged random effects growth curve models confirm the cumulative (dis)advantage mechanism for educational life course inequality in subjective wellbeing. Furthermore, the results reveal substantial cohort variation in life course inequality patterns: regarding life and income satisfaction, the results indicate that the cumulative (dis)advantage mechanism does not apply to the youngest cohorts (individuals born between 1970 and 1985) under study. In contrast, the health satisfaction results suggest that educational life course inequality follows the predictions of the cumulative (dis)advantage mechanism only for individuals born after 1959. While the life course trajectories of highly educated individuals change only slightly across cohorts, the subjective wellbeing trajectories of low-educated individuals start to decline at earlier life course stages in younger cohorts, leading to increasing life course inequality over time. Thus, the overall findings of this study contribute to our understanding of whether predictions derived from sociological middle range theories are universal across societal contexts.