The National Academies of Sciences, Engineering, and Medicine assembled the ad hoc Committee on State-of-the-Science and the Future of Cumulative Impact Assessment to convene state-of-the-science workshops and develop a consensus report to advise the U.S. Environmental Protection Agency on further developing the scientific foundation underlying the practice of cumulative impact assessment. This proceedings provides a summary of a workshop series that the committee convened as part of its information-gathering activities. The series included a community-engaged workshop in New Orleans, Louisiana; a virtual Town Hall with members of the community and Tribal liaison group from across the United States; and a Tribal engagement event in Aurora, Colorado. This proceedings has been prepared by the workshop rapporteurs as a summary of what occurred during the workshops.