This paper assesses the impact of two social security reforms using a calibrated, dynamic life cycle model. It quantifies the long‐run distributional impact of two sets of reforms in France: (1) the 2013 reform of Prime Minister Ayrault, which modified the parameters of a defined benefit (DB) plan, and (2) a hypothetical reform that changes the system to a notional defined contribution (NDC) plan, similar to that in Italy. First, on aggregate welfare, the Ayrault reform and the hypothetical switch to NDC yield contrasting results. The Ayrault reform improves aggregate welfare, which is not the case for the NDC reform. Welfare comparisons are made with respect to the “benchmark economy,” where increases in life expectancy occur and are dealt with only through a higher contribution rate. Second, both reforms yield unequal distributions of welfare changes, with low‐skill workers on the losing end. Under the Ayrault reform, low‐skill workers delay retirement by two years, to age 62. Under NDC reform, pensions for low‐skill workers fall substantially as inequalities during the work life translate directly into inequalities in pensions. The switch to an NDC scheme leads to a more unequal society in terms of asset and welfare distribution.