Yes, you will need to add it to your 2020 return.
If you filed, it is like dropping it into a mailbox - you cannot get it back.
You'll have to wait until your return is either accepted or rejected.
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If rejected, you can make any necessary changes.
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If accepted, you'll need to amend your return.
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To avoid unnecessary delays, do not amend until your original return has been fully processed.
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You can e-file your 2020 amended federal tax return, but most states require amendments to be printed and filed by mail.
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Allow 16 weeks for processing.
See this TurboTax FAQ for help with amending.
You can check the status of your amended return here, but allow 3 weeks after filing for it to show up.