Groundwater levels at or near the land surface represent an undesirable hydrologic condition for most developed settings that can damage or impair the built environment. While many coastal settings have abundant areas of shallow groundwater (e.g., wetlands), these levels can respond to changes in relative sea level and rainfall in spatially unique ways. We use a numerical groundwater flow modeling framework to forecast how groundwater levels change with differences in long-term sea level and recharge rates for the southeastern United States as part our application of the U.S. Geological Survey’s Coastal Storm Modeling System Groundwater (CoSMoS-GW) approach. The results for the coastlines from North Carolina to Florida demonstrate the importance of low-lying topography in limiting the groundwater rise, while steeper coastal topography allows more groundwater level increases. The modeling provides diagnostic present-day and future hydrogeologic conditions through continuous geospatial data products for groundwater head, water table depth, saltwater intrusion, and groundwater flow paths. Importantly, all these outputs describe the long-term conditions of the shallow unconfined coastal groundwater systems that are historically not the focus of groundwater resource studies and are, thus, more poorly constrained than the deeper confined aquifers despite their importance for near surface hazard exposure. The groundwater level and intrusion datasets are the only existing estimate for the unconfined aquifer in many areas and can be leveraged to identify and prioritize portions of the coast needing additional monitoring and modeling efforts.  The Gulf coastline is the next focus of the modeling efforts and the last portion of the coterminous U.S. to be completed as part of the CoSMoS-GW work.