Wall-modeled large-eddy simulations of an airfoil at a high angle of attack are conducted to investigate the predictability of the trailing-edge stall. The result with the equilibrium boundary layer model underestimates the boundary layer thickness and overestimates the lift coefficient compared to the reference wall-resolved large-eddy simulation data. When the non-equilibrium boundary layer model is used, the velocity and Reynolds shear stress profiles in the boundary layer show a reasonable agreement with the reference data. From the analysis of the stress balance in the wall model, the effect of non-equilibrium is strong at the place where the adverse pressure gradient is large, and only the non-equilibrium boundary layer model can reproduce the trend of each stress components. However, even the equilibrium boundary layer model can evaluate the skin friction with a reasonable accuracy except for the laminar flow region near the leading edge. Furthermore, it is also suggested that the calculated skin friction does not have a large influence on stress balance in the boundary layer when the adverse pressure gradient is large. Therefore, it is assumed that the equilibrium boundary layer model can predict the trailing-edge stall using if the laminar flow region is properly treated.