Filed 401K as traditional IRA in 2017

[martiniyin]

I accidentally filed 401k as transitional IRA in 2017 and didn't realize it until now. I did put the amount of 401k when I filed my W-2 and then I put the same amount for IRA reduction. What do I need to do to make the changes? Do I need to file 1040X? I believe I got more tax refund than I should. Does that mean I need to pay the money back with penalties and interest? Thank you.

[MinhT · Accepted solution]

Yes, you need to file an amended tax return for 2017 by filing form 1040X. As you have double-counted the deduction,. you would have to pay additional taxes. With your amended return, you need to enclose a check for the amount indicated on the form 1040X. In the explanation for the amendment, state that you did it by error. The IRS may waive penalty and interest if this is a small amount.

Please see the following TurboTax FAQ for instructions on how to amend your 2017 tax return in TurboTax.

https://ttlc.intuit.com/questions/1894381-how-to-amend-change-or-correct-a-return-you-already-filed

[martiniyin]

Should I also file 540X for state return too?

[MinhT]

Yes.