Apparently not. (with a qualification for a certain multiple employers situation )
IF you had only one employer during 2020, and the only change will be in box 4, showing that the repayment was done, then no wait is needed, nor is an amended tax return required if you filed earlier (assuming that is the only change, or the change was in box 14 for those railroad employees who pay Tier 1 RRTA tax).
Now, if you had more than one employer during 2020, you might have to either file an extension and wait, or file earlier and amend several months later when you get the W-2C....IF...if the final corrected total for box 4 (or box 14 Tier 1 RRTA tax) from all your employers exceeds 8537.40 because you are due a refund of the amount that exceeds that $$ amount. This will only happen if your total W-2 wages exceed137,700 for 2020.
Form W-2 Reporting of Employee Social Security Tax Deferred under Notice 2020-65 | Internal Revenue ...
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"Instructions for Employees
If you had only one employer during 2020 and your Form W-2c, Corrected Wages and Tax Statement, for 2020 only shows a correction to box 4 (or to box 14 for employees who pay RRTA tax) to account for employee Social Security (or Tier 1 RRTA tax) that was deferred in 2020 and withheld in 2021 pursuant to Notice 2020-65, no further steps are required. However, if you had two or more employers in 2020 and your Form W-2c for 2020 shows a correction to box 4 (or to box 14 for employees who pay RRTA tax) to account for employee Social Security (or Tier 1 RRTA tax) that was deferred in 2020 and withheld in 2021, you should use the amount of Social Security tax (or Tier 1 RRTA tax) withheld reported on the Form W-2c to determine whether you had excess Social Security tax (or Tier 1 RRTA tax) on wages (or compensation) paid in 2020.
If the corrected amount in box 4 of the Form W-2c for 2020 causes the total amount of employee Social Security tax (or equivalent portion of the Tier 1 RRTA tax) withheld by all of your employers to exceed the maximum amount ($8,537.40) of tax that you owe, or increases an already existing excess amount of employee Social Security tax (or Tier 1 RRTA tax withheld), then you should file Form 1040-X, Amended U.S. Individual Income Tax Return, to claim a credit for the excess Social Security tax (or Tier 1 RRTA tax) withheld. See the instructions to line 10 of Schedule 3 in the 2020 Instructions for Form 1040 and Form 1040-SR for more information."
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
