If federal is already e-filed and pending, and you need to add information to or modify your return, you need to wait until it is either accepted, or rejected.
If rejected, you can update your return and re-file.
In order to change who can claim you as a dependent, with your return open go to:
- Click Menu (3 horizontal bars in the upper left corner)
- Select My Info and click the edit (the pencil) next to your name
- Go to question 3 and choose the appropriate response
If accepted please see the following regarding amending a return: