This study investigated whether patterns of religious change from early to middle adulthood is associated with patterns of change in filial norms from midlife to later life. Tracking change across 45 years of the adult life span, we link developmental processes occurring at two stages of life using midlife as the point of inflection. Respondents consisted of 436 individuals in the Baby Boom generation who participated in the Longitudinal Study of Generations from Waves 1 (1971) to 9 (2016). We conducted latent class and latent transition analysis to identify religious classes and their transitions over several decades, and latent growth curve modeling to identify change in filial norms. We identified three religiosity classes in Waves 1 and 5—strongly religious, weakly religious, and moderately religious—and five patterns of religious transitions. These transitions were then used to predict change in filial norms between Waves 5 and 9. Respondents who remained weakly religious from early to mid-adulthood reported weaker filial norms in midlife, compared to those who became more religious, and declined more rapidly in their strength of filial norms after middle age. Those who stayed weakly religious also declined more rapidly post-middle age. Our findings link dynamics in religiosity and filial norms across disparate stages of the adult life span and suggest that religious orientations earlier in adulthood are linked to filial norms at time of life when responsibilities for eldercare become a concern for one’s parents as well as oneself.