If you received a corrected or additional W-2, follow the instructions below (choose the link you need) to amend your 2018 tax return.
Amend your 2018 return if you need to change or correct something after you already filed it.
Keep in mind: You have 3 years from the date you filed your 2018 return (or 2 years after you paid the tax due, whichever is later) to file an amended return.