To make changes or add information to an already filed return, you will have to wait until your return gets accepted or rejected to make any changes. Do not make any changes to your e-filed return, it will not go through. The IRS started accepting returns today Feb. 12th, you will have to wait until then to see if your return is accepted or rejected.
If rejected, you can enter or change your information, then re-e-file.
If accepted, you would have to amend your return to make changes or add information.
Also, the Federal amended return (1040 X) will not be available until Feb. 28th (that can be subject to change.) The IRS suggests you wait until your original return has been fully processed before you amend your return.
