The Action Agenda for Historic Preservation in Legacy Cities asserts that new preservation strategies are needed in cities experiencing population loss and disinvestment. The agenda proposes nine action items for preservation in legacy cities as part of a comprehensive and effective approach. The action items are grouped under three themes: shaping a new approach to preservation, adapting existing preservation tools and policies, and supporting place-based collaboration. The agenda is an invitation for people who care about the built legacy of American cities to strategically collaborate as these places are reshaped over the next months and years. Advancing the agenda will require the active participation of preservationists and allied stakeholders across multiple disciplines. It will require creative thinking, innovative partnerships, and the prioritization of funding to meet pressing needs. And it will require all these things now-or yesterday-or ten years ago. There is no time to lose.