Yes, pre-tax income confuses a lot of people. If your HDHP premiums total $2,000 but they were pretax on your paycheck, that means that they're based on income you've earned, but they're re not included on Box 1 of your Form W-2, which are the wages you report on your federal Form 1040.
So when you report your W-2 on your return, you're already getting a tax break. To deduct that $2,000 again -- aka "double dipping" -- you'd be getting twice the tax break that you're actually entitled to.
And since Georgia's computation begins with your federal Adjusted Gross Income (AGI), your tax break would carry over to your Georgia return. So, you don't need to make any adjustment to your state return to reflect the HDHP.
