Yes, you may save and sign out. We automatically save your work every time you move to a new screen, in case you lose your connection.
Also,
when you sign out, your work is automatically saved to our secure
servers so you can pick up right where you left off when you sign back
in. To save & sign out please select the - My Account - at the top
of your TurboTax screen and select - Save & Sign Out-.
Then
when you are ready to return to continue your return please remember to
use the same User ID and password as you did when your started your
return.