When you amend your return, you will just be adding the omitted W-2 to the original return you filed so it will be a "complete" return for all your income and deductions.
Generally, we do not suggest it file an amended return until your initial return has been fully processed.
You can complete the amended return in TurboTax.
The states and IRS share information, so if you amend your federal return and it affects your state return, you need to also amend your state return.
