An alignment mechanism is an action or set of actions that helps medical, social, and public health systems operate in more integrated and coordinated ways, ultimately leading to improved health and health equity for a defined population group of interest. We view systems alignment as a deliberate process to coordinate the work of multiple independent systems and sectors, including the development of shared priorities and goals, shared governance and decision-making, shared financing and resource allocation, and shared data and information. See for example: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7362706/. S4A has studied a variety of novel approaches for aligning systems using rigorous scientific methods to determine their impact on health and health equity. But unfortunately, many promising ideas for systems alignment have yet to be rigorously studied.