Why does my taxable income amount lower than total minus deductions?

[ajmcdevitt]

Total Income 71,673 - 23,300 deductions = 48,373 taxable income. Yet Turbo Tax shows taxable income 22,799.

Why the difference? Is there a soft ware error?

We are both on SS and that is part of our total income. 

[Anita01 · Accepted solution]

Your total income is not what's used in the determination of taxable income.  Rather your Adjusted Gross Income is used.  Only a portion of your social security is taxable.  Look at your 1040 to see how all this is calculated.  Click on Forms in the upper right, then click on the 1040 in the list of forms in your return on he left.