You will need to wait until your returns get accepted or rejected.  If for some reason they are rejected, you can add your 1099-INT form & re-e-file.  If your returns get accepted then you would need to amend your return to add the form.

You cannot amend your return until the amendment form (1040X for Federal) is available which is sometime in mid to late February.  You should also wait to amend your return until your original return has been fully processed.  Amended returns must be mailed, they cannot be e-filed.

To amend with the Online version, Sign back into your return, Scroll down to Your tax return & documents (you may need to select Show), select 2019 and then Amend (change) return.

To amend your 2019 return in the TurboTax CD/Download software:

1. Open the return you want to amend in your TurboTax software program.
2. Make sure your return is exactly as it was when you originally filed it.
   • If you made changes after you filed, undo them. We suggest comparing your on screen numbers with a paper copy of your filed return.
3. Now, make an "amend" copy your return by selecting Save As (Mac: select Duplicate) from the File menu. This preserves the originally-filed return.
   •  Name the copy to distinguish it from the original, like 2019 Amended Smith B Form 1040 Return.
4. You should now be working inside the copy you'll be amending. Inside your program, search for amend and then click the Jump to link.
5. Select Continue on the We'll help you change (amend) your return screen.
6. On the following screen, Did you already file your return? select Yes, I've already filed my return and then select I need to amend my 2019 return. Select Continue and then carefully follow the instructions to amend.
   • Don't worry if your refund meter drops to 0; this is normal. Your calculations will come out correctly in the end.
7. When finished, we'll provide instructions for mailing your amended return, as amendments cannot be e-filed.

3 weeks after mailing your amended federal return, you can start tracking it at the IRS Where's My Amended Return? site. Allow at least 16 weeks for the IRS to process your amended return.

Processing times for amended state returns vary from state to state. If it's been more than 12 weeks since you mailed your amended state return, and you haven't heard anything, we suggest you contact your state tax agency.