If you have already filed your return, you'll need to wait for your tax return to either be rejected or accepted, if it is rejected you can add your Form W-2, correct any other errors on the return and resubmit it.
If it is accepted, you will need to amend your return to
include the Form W-2.
Please be aware that Form 1040X will not be available in TurboTax until mid-February, but
once it is available, you will be able to prepare and print your amended return
so that you can mail it to the IRS. You cannot e-file an
amended return as this cannot be filed electronically. The form is only
filed on paper, so it will need to be printed and filed by mail.
Please see the following TurboTax FAQ for instructions on how to amend your 2016 tax return in TurboTax.
https://ttlc.intuit.com/questions/1894381-how-to-amend-change-or-correct-a-return-you-already-filed
If you have already filed your return, you'll need to wait for your tax return to either be rejected or accepted, if it is rejected you can add your Form W-2, correct any other errors on the return and resubmit it.
If it is accepted, you will need to amend your return to
include the Form W-2.
Please be aware that Form 1040X will not be available in TurboTax until mid-February, but
once it is available, you will be able to prepare and print your amended return
so that you can mail it to the IRS. You cannot e-file an
amended return as this cannot be filed electronically. The form is only
filed on paper, so it will need to be printed and filed by mail.
Please see the following TurboTax FAQ for instructions on how to amend your 2016 tax return in TurboTax.
https://ttlc.intuit.com/questions/1894381-how-to-amend-change-or-correct-a-return-you-already-filed