@partridge
Seeing the long-term capital gain listed on various forms or worksheets does not mean you are being taxed on it. It's not as simple as subtracting the gain from your taxable income, or omitting it on a form. The long-term gain is included in your total income and AGI, but that doesn't mean it is being taxed.
The tax calculation is done on the Qualified Dividends and Capital Gain Tax Worksheet (or possibly the Schedule D Tax Worksheet). It's somewhat complicated, but if you carefully follow the calculations on the tax worksheet you will see that you are not being taxed on the long-term capital gain. If there are no complications that you haven't mentioned, you will probably see your long-term capital gain on line 9 of the Qualified Dividends and Capital Gain Tax Worksheet, which says "This amount is taxed at 0%."
By the way, the long-term capital gain is already included in your AGI. You don't add the gain to your AGI.
