ACCS compiles information on terrestrial and aquatic non-indigenous species (NIS) that are present in the state and assesses the risk that they pose to Alaska’s natural and economic resources. We also research whether invasive species not currently present in Alaska have the potential to arrive, survive, and establish here. Some of the ways we address these questions are through spatial modeling of at-risk habitats, risk assessments based on ecological and socioeconomic potential for harm, and quantifying which pathways are the most probable entry point for biological introductions. We have conducted risk assessments on marine NIS in the Bering Sea, as well as on terrestrial NIS in the Aleutian and Bering Sea Islands and in Alaska’s National Forests. Additionally, biologists at Kachemak Bay National Estuarine Research Reserve actively monitor non-native marine animals, such as European green crabs and tunicates. Our findings provide guidance for monitoring programs and help resource managers and policy makers prioritize species, areas, and pathways of greatest concern.