Do Gambling winnings increase a taxpayers AGI?
First of all, congratulations for this huge gambling win!
Unfortunately your Gambling winnings are included on line 21 of the Form 1040 page 1. Therefore, they are included in the computation of your Adjusted Gross Income.
Accordingly, Gambling Winnings contribute to an increase in your AGI, which in turn will increase the threshold amount required for your itemized deduction's that are subject to the 7.5% AGI limitations.
Don't forget to report all your Gambling losses on Schedule A of your Individual 1040 tax return as these are deductible to the extent of your gambling wins.
"The IRS requires that you maintain records for all gambling losses claimed on Schedule A."