Yes, you can amend just your state return. The steps are identical to filing a federal amended return initially. To do this in TurboTax, see: I need to amend my state return which provides the steps for both TurboTax Online and TurboTax CD/Download.
The directions for TurboTax Online from the above link:
- Sign in to your TurboTax account if you're not already signed in.
- Under Your tax returns & documents (you may need to scroll down or select Tax Home first), select Show to open a list of options.
- Select 2020 and select Amend (change) return, then Amend using TurboTax Online.
- Select the reason you’re amending and continue.
- Answer the questions about your federal return, even if they don't apply. You'll eventually get to the screen Let's get started on your state taxes.
- Keep going and we'll present you with the option to amend. In some states, this appears right at the beginning; in others, it appears towards the end of the state interview.
- When finished, we'll provide printing and filing instructions for the amendment. Your state may take several months to process it.
Once the amendment is triggered, and the correction has been completed, follow the prompts for how to submit it to the state. California requires amended returns to be mailed in. TurboTax will provide you all necessary instructions to file including the address for the mailing.
