Before the passage of the One Big Beautiful Bill Act, retirees started to get hit with tax on part of their Social Security benefits after their provisional income hit a specific threshold. That threshold is $25,000 for single tax filers and $32,000 for married joint tax filers. The income that's counted in provisional income for determining if you meet the threshold includes a limited amount of non-taxable income (like MUNI bond interest), all your taxable income, and half your Social Security.