Do I need to get my W2 corrected if box 12a doesn't reflect my full Roth Contributions for the year?

[Tarheel1]

My box 12a (AA - Roth Contributions) doesn't reflect contributions from my last paycheck which happened before year end where the money way taken out, but the payroll processing company didn't send the money to my 401k till the new year.  Do I need to get my W2 updated to reflect the last paycheck or is it technically correct?

[MaryK4 · Accepted solution]

No you do not have to get your W2 corrected.  Technically it is correct because employers are required to report the income/deductions in the year it was received.  It will be reported on your 2021 W2, but the contribution will count for 2020.