The USA has a long history of national policies that have prioritized and supported coastal development, often at the expense of coastal ecosystem integrity. The emerging and cumulative impacts of climate change, particularly rising sea levels and their associated effects, have influenced the continued dependence on these historical policies, displacing previous goals focused on development to more recent goals prioritizing coastal ecosystem integrity. The purpose of this chapter is to highlight changes that are occurring in two main fields of US national policy – national public disaster relief and publicly funded flood insurance – and examine how these changes differ from past practices. Major factors contributing to this policy evolution are identified, and the potential effects and consequences for coastal ecosystems relative to climate change mitigation and adaptation are examined. Inferences drawn from this work can help show how major policy change can result from an incremental diffusion of new information over an extended period.