Population projections are estimates of the future population. As part of planning, states and localities across the country develop population projections on a regular basis, but methods and resources differ by area, making quality difficult to evaluate. This State and Local Population Projections Database, stored as part of the Applied Demography Toolbox, brings together state and local population projection information and materials from different sources through survey responses and file sharing. The database can be used by population projection developers and researchers for the study and analysis of population projection methods and associated uncertainty.