No. You do not file two tax returns.
Did you efile your original return? If so, you will have to wait for the return to be either accepted or
rejected. Most people won't know until sometime after January 29, unless yours is pulled early for testing.
If your return is rejected, then you can make whatever changes you want and resubmit the efile.
If your return is accepted, however, then the only way to make changes is with an amended return (Form 1040X).
If
that happens, then it's recommended to wait on any Federal refund to
arrive first before amending. TurboTax has not yet opened its online
amending process anyway. So do NOT start one.
An amended return has to be printed, signed, and mailed. It cannot be efiled.
NOTE: In the meantime, do not make any changes to your already-filed return. If you end up needing to amend, your return has to start off exactly like it was when it was efiled.
If you end up having to amend the Federal return, then you may have to amend the State return (if applicable) as well.
