When selecting to amend 2023 return, TurboTax reset Federal tax due to $1,598, not ZERO!!!

[Bren7]

The only change I needed to reflect was a missed 1099-INT form for $18.  On the 1040x form that I (reluctantly) went on to produce, everything looks OK in the Income and Deductions section, only displaying a net change of $18; however, on line 6, for Tax Liability, it shows a net change of $1,598!!!   Also, just below the line 6 description "Tax. Enter method(s) used to figure tax (see instructions):", it shows QDCGTW.

How can I all of the sudden owe 1,598 for reporting an additional $18 in interest received?!?  Actually, before I do anything except say I want to amend return.  Original return showed tax due of $67.

As soon as I cancel the amended return (Remove amendment), it tells me that "If you've added info since starting this amendment, it will stay in your return", and then the Federal tax due reverts to what it was before I ever tried to amend the return, plus an additional $8.  That is more what I'd expect, (even though I can't believe that I have to pay almost 50% of the additional interest reported in federal tax).  

The state tax due (VA), properly reset to zero upon selecting to amend return, and it showed only $1 of additional tax due.  

I've tried a couple times to redo the amended return, and everytime the same thing happens, it resets the Federal Tax Due monitor to $1,598.   

[DianeW777]

The QDCGTW stands for qualified dividend and capital gain tax worksheet which is found in the 1040 instructions. If you had qualifying dividends and/or capital gain transactions this worksheet must be used to calculate your tax.

The change of $18 income could and often does put you in the next tax table income level (moving  to the next income increment) and could create an additional $8 of tax. 

Make sure the amendment is accounting for the amount of tax withheld on your W-2s.   The best way to see what's happening is to use the 1040 from your original return and compare it line by line to the 1040 in the amendment. This will allow you to zero in on what's being changed.  If the 1040X shows the balance due of $8 it should be correct. 

[Bren7]

Thank you for your advice.  I went back and compared the 1040 from my original return to the new 1040 to be included with the amended return and the only difference is the $18 in income and the new 1040 shows my balance due of $8 more than the original (Original showed $67 due and new 1040 show $75 due).  So that part looks good!

The problem is on the 1040-X that TurboTax generated.   Both the cover letter and the 1040-X shows I owe $1,598, as opposed to the expected $75).   As I mentioned, as soon as I clicked to create an amended return in TurboTax Premier, it change the Fed Tax Due monitor number from $67 to $1598 (but it changed the state tax due to 0, and the message link in Turbo Tax "Why did the refund monitor just change to $0" indicated that it resets the tax to 0, but it did NOT for the federal tax). 

Therefore the 1090-X does not reflect the difference between the original and new 1040.   Line 6 on the 1040-X shows a net change of $1598 for tax and the "Correct Amount" Column C total on Line 6 does not agree with the newly generated 1040.  And Line 18 ("Overpayment, if any, as shown on original return or as previously adjusted by the IRS") on the 1040-X shows $1,523, and I don't know where that came from!!  

I think TurboTax has some kind of error in generating the 1040-X.  

So what I did that appears to fix the problem:  I went into the forms mode, opened form 1040-X, and then I went to the section that says "Original 2023 Return OverPayment Smart Worksheet", and changed the amount from $1,523 to zero.  I have no idea what causes that number to be there.  But making it 0 causes the 1040-X to agree with the original and new 1040 and the balance due is only $8 more for the $18 increase income, as opposed to $1598 more!

[Bren7]

Additional info..... I figured out the source of the problem.  It appear TurboTax was very confused with the excess advance premium tax credit I reported on form 8962 and that amount was correctly reflected on 1040 Schedule 2 and then added in to my tax on 1040.  However, for some strange reason that number was left out of the tax info on the 1040-X showing original amounts, so it thought there was a big increase in my tax because of that adjustment.  So, when I opened forms to edit the 1040-X, I corrected the original amount of tax liability on the 1040-X and made sure all the before and after compares were correct. 

[john_m95]

I had a similar problem with TurboTax Premier 2023. When I start to amend the original file prior to change, the state tax set to zero, but not for federal tax.