Mistakes found during review & can't correct them. both Fed & State returns.

As long as you haven't filed .You can get back in to make corrections .(you just have to trick it a little) If you have already filed you would need to file amended returns.

To access your State tax return to make corrections after printing, but before mailing your return, you can "add a state" to make changes:

Please try this:
    Sign In to Turbo Tax Online
    Click "My Turbo Tax" menu.
    Press "Visit My Tax Timeline"
    Under the "SOME THINGS YOU CAN DO" heading, choose "Add a state" (You're not really adding a state, this allows you to get back into your return).
    Click"Federal"tab then press "Edit" to make changes.