You can make changes to your tax return before you actually forward it to the IRS for approval.
To change your info in TurboTax Online before filing, follow the steps below:
1. Sign into your Online account.
2. Click the button that says "Take me to my return".
3. On the left navigation panel select "My Info" or any other section that you wish to revise. To edit the information click on the pencil icon next to the appropriate section.
4. Begin editing each section that you need to until the return is ready to be filed.
Please see the FAQ below for more information:
https://ttlc.intuit.com/community/after-you-file/discussion/want-make-changes-before-filing/00/570626
If you have already submitted your return to the IRS, you will need to wait and see if its rejected or accepted. If it's rejected, you can go back in and change the year.