What if I filed my return already but received another W-2?
If you e-filed your return already and it hasn't been accepted yet, just sit tight. There's a small chance it may be rejected. If it gets rejected, you'll be able to add your other W-2 to your return and then e-file it again.
If your return has already been accepted, or if you already mailed it, you'll need to amend your return to so you can add your other W-2 to your return.