Taxes on Benefits Social Security is paid in with after-tax dollars but may be subject to tax if annual income exceeds a base amount. A single taxpayer's base is $25,000. Married taxpayers filing jointly have a base of $32,000. Married taxpayers filing separately have a base of zero. Suppose Lorenzo is retiring this year at age 67. The following table shows his data. $31,500 $275 Part-time salary Annual dividends Annual savings account interest Annual interest on Denver municipal bonds $2,500 $1,350 Based on the income calculated, Lorenzo will have % of his Social Security benefits taxed