Raise the tax rate two points, split between employer and employee, and raise the full retirement age from 67 to 69. Phase both in same as was done starting in the 1980s. That process concluded, by the way, only just this year.
It was going on all along and you never even noticed.
Doing this again will make Social Security solvent until 2100.
AARP to Congress: ‘We strongly object to fast-tracking Social Security changes’
