The entire $5.3 trillion shortfall over the next 75 years would be wiped out if payroll taxes were increased by 1.1 percentage points for both workers and employers. It would also disappear if Congress started taxing all wages, not just those below $106,800, said the Senate report, citing projections by the actuaries at the Social Security Administration.

On the benefits side, more than three-fourths of the shortfall would vanish if Congress reduced annual cost-of-living increases by 1 percentage point each year. Social Security recipients get annual increases based on inflation. This January, for the first time since automatic adjustments were adopted in 1975, there was no increase because prices decreased last year.

About 23 percent of the shortfall would be gone if Congress gradually increased the age when retirees qualify for full benefits from 67 to 68. Nearly a third of the shortfall would disappear if the full retirement age were gradually increased to 70.