Yes, most likely you need to file an amendment. However, please wait first until your return is either rejected or approved and also wait until you have received your refund or your payment has cleared.
If it's rejected, you can return to the program to
add the 1042-S while fixing the error.
If your return is approved, you would need to
amend if adding the 1042-S information changes your original refund amount or tax
due. To amend, please click here 2018 Amend. Follow the instructions in the program
and it will tell you if it will make a change.
To amend, you will need to submit by mail a Form 1040-X with any additional tax forms where your 1042-S triggers. Make sure to attach the 1042-s to the tax forms as well. If the new information creates a difference in the total refund or tax due, you will need to amend both federal and state tax returns.
