If you have actually submitted an efile; i.e., if you clicked the orange "Transmit My Returns Now" button, then you'll need to wait to see if your return is accepted or rejected by the IRS when they start processing returns on January 27. Each year a few returns are pulled early for testing purposes, and a few users have reported an early acceptance, but most users won't find out their efile status until on or soon after January 27.
If the IRS accepts the efiled return, then the only way to make any corrections is by preparing an amended return Form 1040X.
If the IRS rejects the return, then you'll have the opportunity to make any corrections and resubmit the efile.
