I've already submitted my tax return for 2022 and received the refund.
Today, I received an W2C from my employer. The "social security wages", "Social Security tax withheld", "Medicare wages", and "Medicare tax withheld" amounts are changed. But the Wages and Federal income tax withheld are blank (not changed). In this case, do I need to file a tax amendment?
No, you do not need to amend the 2022 tax return for changes to SS wages, SS taxes, Medicare wages or Medicare taxes.
If you had only one employer in 2022, you do not have to file an amended return.
You should file an amended return if you had more than one employer, and the change in the Social Security tax creates or changes the amount of excess Social Security tax withheld. If the tax return that you filed has an amount on Schedule 3 line 11, the change in Social Security tax will change or eliminate that amount, so you should file an amended return. You should also file an amended return if the change makes your total Social Security tax for the year, for all employers, more than $9,114 (for 2022).
If you filed as married filing jointly, add up only your own Social Security tax (if you are the one who got the W-2c). Do not include your spouse's Social Security tax.
In addition to the Social Security considerations above, if Medicare wages (box 5) on your W-2, either before or after the correction, are more than $200,000, you must file an amended return because the change in Medicare wages will change the Additional Medicare Tax on Form 8959, or Form 8959 will be added to your tax return. If the total Medicare wages on all of your W-2s, plus net self-employment income, is more than $200,000, you also must file an amended return, because the change in Medicare wages will change or add Form 8959.