Mass loss from the Antarctic Ice Sheet is the most uncertain contribution to future sea-level  rise, and this uncertainty stems from uncertain future climate, uncertain parameters in ice-sheet models, and deep uncertainty in the representation of key physical processes in ice-models and their coupling to the ocean and atmosphere.  We address these uncertainties using ensembles of simulations with E3SM’s ice-sheet component, MALI. First, focusing on the historically stable Amery Ice Shelf sector, we use Bayesian calibration, enabled by Gaussian Process emulation, to constrain uncertain model parameters and generate calibrated projections of future sea-level contribution from this region under low and high emissions scenarios through 2300. We find that substantial sea-level contribution is possible should changing climate allow warm offshore ocean masses to reach the ice shelf, contrary to prevailing assumptions that this region will continue to be stable under plausible future climate forcings.  Rapid removal of the ice shelf appears possible in the 22nd century as the switch from cold- to warm-cavity conditions drive an order-of-magnitude increase in ice-shelf melting, causing acceleration of ice flow into the ocean and 43-135 mm of sea-level contribution (5-95th percent confidence interval) at 2300 from this one sector.  Building on this analysis, we secondly perform parameter sensitivity experiments of the entire Antarctic Ice Sheet under climate forcings from CMIP5 and CMIP6 models. While parametric uncertainty remains large, the choice of climate forcing and choices regarding ice-sheet model fidelity are the dominant sources of uncertainty in our predictions of sea-level rise from Antarctica. Finally, we discuss progress towards coupling of MALI to the land and ocean components of E3SM, including the implantation of evolving ice-shelf cavities in MPAS-Ocean.  The unique ability to dynamically simulate the Antarctic Ice Sheet in E3SM is anticipated for v4 and will help elucidate sea-level uncertainty related to ice sheet/climate interactions.