"Under current law, the share of retirees with inadequate income will increase from 26% in 2020 to 45% by 2090, including a sharp increase after 2034. Most of the income gains from working longer accrue to workers before retirement, with only a modest portion of the gains directly increasing incomes in retirement.... By 2065, more saving reduces the share of Social Security beneficiaries unable to replace 75% of preretirement earnings by 5 to 13 percentage points."