401k Overcontribution in 2023, do I need to file an amended return and can I use TurboTax to do it

[ew1721]

I over contributed to a 401k in 2023 and received the excess contributions back in 2024 along with a 1099 with distribution code "P".  I think I have to file an amended return for 2023 to report the excess contribution. Can you confirm that I need to file an amended return?

Also, I didn't use turbotax to file the 2023 tax return, (but I'm using it to file my 2024 return). Can I use turbotax to file the amended 2023 return?

[DanaB27]

If you didn't report the excess deferral on line 1h on your 2023 Form 1040 then you will need to amend your 2023 return.

Yes, you could use TurboTax to amend the return but you will first have to buy the 2023 software and recreate your original return before you can amend it. It might be easier to amend it where you originally filed the 2023 return.

Please see How do I amend my federal tax return for a prior year?

[ew1721]

Thank you Dana,

I figured out how to report the returned contribution on submit an amended federal 1040x. The IRS makes it relatively easy.

But I am confused on how to correct my California state tax return (Form 540). California requires that I submit 540x, similar to the IRS's 1040x. However, California also requires that I correct and resubmit the entire Form 540 along with Schedule CA (California Adjustments) .

My question is this: where on the 540 and the Schedule CA do I report the returned 401K contributions?

[DanaB27]

When you enter the 2024 Form 1099-R with code P in the federal interview then this amount is added on line 1h on the federal Form 1040. This increases the federal adjusted gross income, which is also entered on line 13 on Form 540. Schedule CA has the amount from the Form 1099-R listed on line 1h (Federal Amounts). Everything is carried over automatically from the federal return.