If you receive a corrected W-2 form after you already filed your tax return, you may need to file an amendment.
In general, you should file an amended return if you need to provide more or new information that affects your tax calculations. This includes amending you residency or filing status, the number of dependents you can claim, correcting total income, credits or deductions claimed or not on the original return.
Important: You do not need an amended return if the change on the W2-C form is regarding your name, address, taxpayer ID or Social Security and Medicare wages and taxes (FICA) in boxes 4, 5, 6 and/or box 7.