TurboTax is calculating the wrong value for Federal tax. Too low by about $2k.

[croftair]

Also the value does not change if I change my Property Tax amount (which changes my taxable income).  If I change any other value, the fed tax does change.  If I change Property Tax, fed tax does not change but state tax does.  I tried entering Property tax a couple of different ways (i.e. you can enter it alongside a mortgage, or enter it separately). Same result.

I reviewed a response to a similar question and can provide 2 details: I am definitely into Itemized deductions (not standard) 

AND...an update, I learned from reviewing the forms that I AM subject to AMT, which is where this is coming from.  The summary shown in "Federal Review" simply does not show the right values for tax owed.  The AMT is what is causing my property tax amount to be ignored.

[DDollar · Accepted solution]

Yes, the AMT will prevent (or limit) you property tax deduction from having any effect on your tax return.  I am confident TurboTax is calculating your tax correctly.  There are lots of moving parts in a tax return.  When you get to the point where you are paying AMT, you may also be subject to the phase out of exemptions and itemized deductions and subject to the net investment tax, etc.  And if you have any capital gains or qualified dividends, those are taxed at at different rate.  TurboTax does have an accuracy guarantee, so if your tax is calculated incorrectly, TurboTax will reimburse you for any penalty and interest you have to pay as a result (they don't pay the tax).