have you e-filed and was it accepted or have you mailed in your return
if you haven't yet e-filed successfully you can correct the w-2
if you mailed it in or filed and it was accepted you have to wait until it's fully processed and then file an amended return
The return cannot be changed at this time, and you should wait until the return is either accepted or rejected. If your return is rejected, you will be able to modify it before you resubmit.
If your return is accepted, you can amend or correct your return if there is a corrected W-2. You will want to wait until your original return is processed. Sometimes the IRS makes adjustments there; they might catch the update when they process your return. You do not want two versions of your return in process at the same time. There is no additional charge to use Turbo Tax to amend your federal or state return. Many, many people have this happen every year. It is a very common thing to have a late or updated form and need to file an amendment for federal and/or for the state.
Below is a Turbo Tax FAQ with step-by-step instructions to amend.