Why my tax liability does not change when i add dependents

[vreuven]

I am testing TurboTax with and without dependent and the 'Federal Tax Due' amount does not change. 

[SweetieJean]

Be sure you are answering all the dependent questions correctly and completely.

[vreuven]

I answered all questions and am getting this message "Your Total Dependent Deductions (so far) $4,050". I also deleted the dependents entry and reenter it. NO CHANGES TO 'Federal Tax Due' amount

[Lisa995]

If the only tax that's due is a penalty of some kind, changing the dependents wont change the tax due.  Look at the actual forms so you can see what's actually happening on the return.

The $4050 is a deduction/reduction from INCOME, not from tax due.

[VolvoGirl]

First of all I hope you are not testing in your real 2016 return.  Have you filed 2016 yet?  Are you testing for 2016 or for next year 2017?

Maybe you are already getting back all the refund you can and adding more dependents or deductions won't increase it.

[SweetieJean]

OP says 'Federal Tax Due'

[vreuven]

Thanks for the concern but I am not testing in real 2016 return. 🙂

I printed both forms (with and without Dependent) and here are the differences: With dependent, Line 42 Exemptions: $12,150, line 44 Tax: $22,187, line 45 AMT: $3,174
Without dependent, Line 42 Exemptions: $ 8,100, line 44 Tax: $23,200, line 45 AMT: $2,161

I don’t know why these figures changed just because I added a depended.

[rjs · Accepted solution]

Ah - It's the AMT. Exemptions for dependents are disallowed under the AMT. When you are subject to AMT, you do not get any exemption for dependents, so adding a dependent makes no difference in your tax.

[SweetieJean]

"tax liability does not change" 

Well, the tax DID change, by more than $1,000.  You got an extra $4,050  income (not tax) deduction for the dependent.  That translates to about a $1,000 tax savings if you are in the 25% bracket.  But then the AMT went up.  That's a different tax.

https://turbotax.intuit.com/tax-tools/tax-tips/IRS-Tax-Return/Alternative-Minimum-Tax--Common-Questi...