AGI is gross income before the std deduction. AGI is line 11 of the 2020 form 1040.
Even so..."Taxable Income" (line 15 of the 2020 form 1040) can not go lower than zero. i.e. zero is the lower limit...after deductions have been subtracted.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
