BackgroundThis study views sustainability after the exit of development assistance for health (DAH) as a shared responsibility between donors and recipients and sees transitioning DAH-supported interventions into domestic health policy as a pathway to this sustainability. It aims to uncover and understand the reemergent aspects of the donor–recipient dynamic in DAH and how they contribute to formulating domestic health policy and post-DAH sustainability.MethodsWe conducted a case study on two DAH-supported interventions: medical financial assistance in the Basic Health Services Project supported by the World Bank and UK (1998–2007) and civil society engagement in the HIV/AIDS Rolling Continuation Channel supported by the Global Fund (2010–2013) in China. From December 2021 to December 2022, we analyzed 129 documents and interviewed 46 key informants. Our data collection and coding were guided by a conceptual framework based on Walt and Gilson’s health policy analysis model and the World Health Organization’s health system building blocks. We used process tracing for analysis.ResultsAccording to the collected data, our case study identified three reemergent, interrelated aspects of donor–recipient dynamics: different preferences and compromise, partnership dialogues, and responsiveness to the changing context. In the case of medical financial assistance, the dynamic was characterized by long-term commitment to addressing local needs, on-site mutual learning and understanding, and local expertise cultivation and knowledge generation, enabling proactive responses to the changing context. In contrast, the dynamic in the case of HIV/AIDS civil society engagement marginalized genuine civil society engagement, lacked sufficient dialogue, and exhibited a passive response to the context. These differences led to varying outcomes in transnational policy diffusion and sustainability of DAH-supported interventions between the cases.ConclusionsGiven the similarities in potential alternative factors observed in the two cases, we emphasize the significance of the donor–recipient dynamic in transnational policy diffusion through DAH. The study implies that achieving post-DAH sustainability requires a balance between donor priorities and recipient ownership to address local needs, partnership dialogues for mutual understanding and learning, and collaborative international–domestic expert partnerships to identify and respond to contextual enablers and barriers.