Why doesn't "Federal tax due" update after AMT is calculated?

[tavennerfb]

TurboTax tells me I owe an additional $4200 tax due to AMT, but it doesn't update the "Federal Tax Due" box, which means when I file for extension, it doesn't give me the updated amount to pay.

[jerry2000 · Accepted solution]

The AMT is already included in your Federal Tax Due. Switch to the Forms mode by clicking the Forms icon, find   1040  in the list of forms on the left, click on that to open it. Scroll to the second page and you will see the AMT amount as one of the items that make  up your total tax due.

[tavennerfb]

Helpful, but not the answer.  My tax before running the AMT calc was $3300, after running AMT was $7000.  However, the "Federal Tax Due" block did not update, and when I ran the 4868 Extension, it prompted with the $3300, indicating that the program didn't recognize that AMT had been calculated.

[jerry2000]

Switch to the Forms mode by clicking on the Forms icon in the upper right of your screen. Then find and click on 1040 in the list of forms on the left. Once the 1040 opens scroll to the second page. Scroll to Line 45, then right click on the number. In the popup select Data Source  and that will show you how the AMT was calculated.

[tavennerfb]

I must not be making myself clear, or this is an automated answer.  AMT IS being calculated, but the new amount of tax due to the AMT is NOT being updated in the "Federal Tax Due" window.  Therefore, when I go to file an extension, the prompted tax due amount is the PRE-AMT amount, NOT the AMT amount.  I'm trying to figure out why TurboTax is not updating the Federal Tax Due window.