According to the 1040X instructions:
Attach any schedule or form relating to the change. For example, attach Schedule A (Form 1040) if you are amending Form 1040 to itemize deductions. If you are amending your return because you received another Form W-2, attach a copy of the new W-2. Do not attach items unless required to do so.
This includes any additional or corrected Forms W-2 you received after you filed your original return. For more information, see the 1040X instructions (link included above).
