Is it a bug that Turbotax puts $31500 in line 2a of form 6251 when I am married filing jointly, itemizing deductions, and the amount of the itemized deductions is 0?

[blundell]

In form 6251, Turbotax appears to be adding back the amount of the standard deduction to my taxable income for AMT purposes even though I am not taking the standard deduction. Line 12e of Form 1040 is 0.

[DaveF1006]

AMT taxable income always starts from a base that assumes the standard deduction is not allowed, even if you didn’t take it on your regular return. That’s the core reason Form 6251 adds back the standard deduction amount.

Under the AMT system, Congress created a parallel tax calculation that removes certain tax benefits. One of the biggest differences is:

• The standard deduction is completely disallowed for AMT purposes.
• This rule applies even if you itemized and even if your itemized deductions were $0.

The IRS explains that AMT is computed by “eliminating or reducing certain exclusions and deductions” when calculating AMT income . The standard deduction is one of the deductions eliminated.

So when Form 6251 starts its calculation, it must reconstruct your income as if you had taken no standard deduction at all. That’s why line 2a adds back the standard‑deduction amount for your filing status, even if you did not claim it on your return.

[blundell]

Thanks for your reply! Just to be clear, are you saying that in an example case where:

* My gross income is $100000

* I take itemized deductions and have $0 in itemized deductions, so my adjusted gross income is $100000

* I'm married filing jointly

The correct adjusted gross income for AMT reporting purposes is $131500 rather than $100000? That seems very surprising, as it's essentially adding income that I never made in the first place.

Thank you,

Colin

[DaveF1006]

Yes, that is correct because your Standard Deduction amount of  $31,500 is being added back for AMT purposes.  This is added back regardless of what deduction you chose to take. As I mentioned in my post:

Under the AMT system, Congress created a parallel tax calculation that removes certain tax benefits. One of the biggest differences is:

• The standard deduction is completely disallowed for AMT purposes.
• This rule applies even if you itemized and even if your itemized deductions were $0.

So regardless, $31,500 is added back for AMT purposes.

[user17733704952]

Hi Dave, is this correct?  The instructions to Form 6251 say the following which indicates line 2a should be the amount on Sch A, line 7 if you are not taking the standard deduction and filing Schedule A instead.

Line 2a-Taxes

Enter the amount of all taxes from Schedule A (Form 1040), line 7, except any generation-skipping transfer taxes on income distribution.

If you aren't  filing Schedule A (Form 1040), then enter the standard deduction amount that you reported on Form 1040 or 1040-SR, line 12e.

[RobertB4444]

Yes, the 6251 takes the taxes or the standard deduction into account on that line.

[user17733704952]

My version of TT Deluxe is only taking the standard deduction into account.  When I itemize deductions, it does not populate line 2a with the Sch A, line 7 amount but continues to incorrectly insert the standard deduction amount.  Please refer to the IRS instructions for that line.

[RobertB4444]

Are you itemizing deductions with a lower amount than the standard deduction?  If so, the system may be reverting back to create the lowest possible tax bill.

[user17733704952]

Yes, I do have a lower amount of itemized deductions, as I have for a number of past years. TT has never reverted to the standard deduction in any past years on Form 6251 and shouldn't this year either.  How to do I fix that so it allows me to use itemized deductions for Form 6251?

To further note - TT includes my itemized deduction amount on my 1040 and also includes a supporting Schedule A, but does not use the Sch A amounts when completing Form 6251 as it has in prior years.

Possible solution - if I double click on the amount in Form 6251 line 2a it takes me to my Schedule A which is "blank" for line 7.  If I populate line 5a with with a "0" it then calculates line 7 and takes that amount (zero) to Form 6251 line 2a.

[LeticiaF1]

When you itemize deductions using Form 6251 for AMT, you must add back some of your deductions.  In this case if TurboTax determines that your Standard Deduction is more advantageous, then it will select it for you.  If you want to use your itemized deductions, you can switch between deductions in the program.

TurboTax Online

1. Go to the screen: Based on what you told us, [either Standard Deduction or Itemizing deductions] is right for you, and select Change my deduction.
2. On  Which deduction do you want to take this year? popup, you'll see the dollar value of each deduction type.
3. Select the type of deduction you want and select Continue twice.

TurboTax Desktop

1. Open or continue your return.
2. Select Federal Taxes.
3. If using Home & Business, select Personal.
4. Select Deductions & Credits.
5. When asked how you want to enter your deductions and credits, select I'll choose what I work on.
6. Scroll all the way to the bottom of the Your 2025 Deductions & Credits screen and select Done with Deductions.
7. Continue until you see The Standard [or Itemized] Deduction is Right for You!
8. Select Change my deduction and choose which one you'd like.
9. Select Continue to apply any changes.

How do I change from the standard deduction to itemized (or vice-versa)?

@user17733704952 
 

[user17733704952]

Thanks, Leticia.  I had already "forced" TT to itemize instead of taking the standard deduction.  That was not the issue.  In prior years when I "forced" TT to itemize and Sch A, line 7 was "blank", TT understood the "blank" to be a zero and moved a zero to Form 6251 line 2a.  

For my 2025 return, when TT saw a "blank" in Sch A line 7 it defaulted to my standard deduction on Form 6251, line 2a.  It was only after I went into Sch A and manually entered a zero into Sch A, line 7 that TT moved a zero to Form 6251 line 2a.  Not sure if this was an intended change or not in the 2025 program.  But it now works.

[xiangjun_wu]

I am running into the same issue. Apparently a bug. Can't believe Turbo Tax has such a simple bug a few days before 4/15. Please fix it asap or I'll have to do my tax return with a pen!

[xiangjun_wu]

How did you go into "Sch A and manually entered a zero into Sch A, line 7 "? I don't know how to get into a tax form and manually change a number and have other forms change calculation automatically. I am paying for the DIY version. Do I need to pay for the full service version to get that capability? Really need this as 4/15 is getting close. Thanks!!

[xiangjun_wu]

I simply entered $0 on one of the step-by-step guide for schedule A state and local taxes. My AMT suddenly disappeared. Don't need to manually change the form. Hope TT could fix it though.