To get back in to your return, make changes, and then e-file your return:
- In TurboTax Online, sign into your account.
- Select Tax Home in the left menu.
- Scroll down to Your tax returns & documents.
- Select 2018, and then select Add a State (you're not actually adding a state, this just gets you into the right menu).
- Select Federal or State from the left menu and navigate to the are you need to correct.
- Select File in the left menu.
- On the Just one more step screen, follow steps 1 and 2 if you haven't already.
- Select the Start button to the right of Step 3.
- On the Let's get ready to e-file screen, select I want to e-file.
- Follow the instructions to e-file your return.