This article analyzes changes in norms of filial care for elderly parents and expectations of old-age support from children, based on a series of national surveys of currently married women of reproductive age in Japan. The analysis suggests that norms of filial care for elderly parents were fairly constant from 1963 until 1986, when a major weakening of norms began. The sudden normative shift after 1986 is conceptualized as a rapid diffusion process, which appears to have been triggered by government efforts to shift some of the burden of caring for the elderly back to families. In contrast to norms of care for elderly parents, expectations of old-age support from children have declined steadily over time, adapting continuously to changes in underlying socio-economic and demographic conditions. Overall, the findings suggest that government efforts to shift the burden of caring for the elderly back to families may not be successful.