I am filing amended tax returns for year 2015 because I did not adjust the cost basis for ESPP stock sale. If this was the only change, which forms do I need to attach?

[punekr]

I am filing amended tax returns for year 2015 because I did not adjust the cost basis for ESPP stock sale.

I learned how to correctly enter all the information for cost basis calculation in Turbotax while filing 2016 tax return. So I used Turbotax 2015 to amend my 2015 return.

This is the only change in my amended tax return. While mailing, which forms do I need to attached in addition to all the standard forms printed from Turbotax ?

[TomYoung]

There's no "in addition to all the standard forms printed from TurboTax"; you mail in all the Forms and Schedules that changed from your original "as filed" income tax return along with the Form 1040X.  (It would be nice if TurboTax, understanding that you're amending, would print out a nice packet consisting of Form 1040X and every Form and Worksheet that's different than your "as filed" income tax return, but it doesn't.  You'll need to select what Forms and Schedules to print.)

Off hand it seems like your Form(s) 8949 where the sales were originally reported would change along with Schedule D.

Tom Young

[Snowy_Desert]

Hey there, I’m in the same boat but for 2023. I just realized that I had to put the adjusted cost basis for ESPP. The difference is about $2k to my benefit. Did you end up amending? What forms did you mail out? 

[AnnetteB6]

You will most likely need to include Form 1040X, along with Schedule D and Form 8949.  Changing your Federal return may also suggest that your state return should be amended as well.

See the following TurboTax help article for instructions to amend a 2023 tax return:

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

@Snowy_Desert 
 

[Snowy_Desert]

Thank you @AnnetteB6 . Will TT Premier 2023 allow me to e-file? In the past, it used to only be done by mail. Also, I have not yet filed my 2024 tax return, and I carry forward a capital loss. Do you recommend I amend my 2023 before filing my 2024 so TT Premier 2024 is updated on the previous 2023 data?

[DianeW777]

No. You do not have to wait to file your 2024 tax return as long as you have the correct capital loss carryover. 

For the 2023 return: If you're amending your return for 2023 or earlier, you need to print and mail your amended return. Follow these instructions to amend a prior-year return.

@Snowy_Desert