We investigate the evolution of the Laurentide Ice Sheet (LIS) during the last deglaciation by calculating its surface mass balance (SMB) using the isotope-enabled transient climate model experiment iTraCE. Two melt-rate frameworks are developed and compared, including a new parameterization of the refreezing of snowmelt and liquid precipitation, along with statistical downscaling of model output. The modeled SMB is then compared with a time series of LIS mass-loss rates inferred from the ICE-6G reconstruction. SMB from iTraCE aligns well with ICE-6G mass loss after ~18 ka, but prior to this time SMB exceeds ICE-6G melt rates, indicating potential model bias. We also find that LIS melt accelerates during the Bølling–Allerød and slows during the Younger Dryas. Additionally, meltwater forcing and expanded sea ice during stadials dampen LIS melt, highlighting a negative climate feedback. 