This paper uses a calibrated dynamic life-cycle model to quantify the long-run distributional impact of two opposite Social Security reforms: modifying the parameters of a defined benefit (DB) plan (such as in France with Ayrault’s reform) or switching to a notional defined contribution (NDC) plan (such as in Italy). Both reforms yield an inequal distribution of welfare losses. Low-skilled workers are the main losers of the reforms. This is so for different reasons in each reform. In the case of Ayrault’s reform, low-skilled individuals delay retirement by 2 years, up to age 62. In switching to a NDC scheme, low-skilled workers’ pensions fall substantially. In NDC schemes, inequalities along the working-life are directly translated into inequalities in pension levels. The switch from a DB plan to the Italian reform yields substantial welfare losses, pensions drastically fall, and individuals save more. Since low-skilled workers do not save as much as middle or high-skilled workers, the switch to NDC schemes leads to a more unequal society in terms of asset distribution.