An important outcome of Arctic Coastal Dynamics is the segmentation and characterization of the entire circum-Arctic coastline by regional experts which is presented in this data set. This data set contains data on coastal morphology, composition, dominant processes, ground ice, and environmental forcing parameters such as wind speed, storm counts, melt season, and wave energy. A listing of the variables included in the coastal classification can be found in Appendix A of the ACD II Science and Implementation Plan (2006). This information is available for over 800 segments, covering the coastline of all eight regional seas of the Arctic Ocean. The length of individual segments is variable (median length is 38 km), and depends on classification parameters and data availability. The segmentation format is scalable, allowing the adoption of future digital coastlines and the integration of additional data at higher spatial resolution. An assessment of the data quality for the more important quantitative variables has just been completed and the data will be publicly released on an Internet Map Server (IMS). The goal of the IMS will be to allow individual users to prepare their own maps displaying the region and variables of interest. The Arctic Coastal Dynamics (ACD) program is a multidisciplinary, multinational program with the goal of understanding circum-Arctic coastal dynamics as a function of environmental forcing, coastal geology and cryology, and morphodynamic behavior. The ACD program was formed under the auspices of the International Permafrost Association (IPA), and is an official project of the International Arctic Sciences Committee (IASC). The ACD program is currently focused on developing a circum-Arctic estimate of sediment and organic input from coastal erosion to inner shelf. Studies indicate that coastal erosion forms a major source of the sediment input and total organic carbon (TOC) input to the Arctic seas.