Abstract The extent to which coastal sea levels co‐vary with open‐ocean variability is explored through evaluation of a balanced dynamics framework relating sea level with pressure, density, and velocity along the continental shelf and slope seafloor. Using high‐resolution regional ocean model output, we develop and evaluate this relationship at 34 stations along the US East Coast. Variability in the extent of cross‐shore connectivity is explained through joint consideration of density and topography structure, an evaluation of steric setup. In the northern sector, reconstructed coastal sea levels have high skill over the continental shelf, while further south, skill increases are achieved when considering variability over the continental slope. These differences are attributed to differing seafloor hypsometries that shape density and along‐shore current structure. Results reveal regions of influence for points along the coast and establish a dynamical link to offshore changes in density classes associated with large scale ocean dynamics.