The tax calculation is based on your taxable income, not AGI. What exactly did the IRS letter say? Did it say anything else was wrong besides the amount of tax? Changes to other things in your tax return could change the tax amount. That doesn't mean that the original tax calculation was wrong. The original calculation was correct based on the original information in the tax return.
There are seven different methods that can be used to calculate the tax on your tax return, depending on the types of income and other factors. Some of the seven methods can get very complicated. Since we can't see your tax return, it might not be possible for anyone here in the community to check the calculation of the tax.
Did you file your tax return with TurboTax Online or with the CD/Download TurboTax software?
