Why is my Roth 401k being deducted from my taxable wages?

[ThisIsSoTaxing]

Since my Roth 401k is supposed to be deducted after taxes, I would expect that the amount I contribute would be included in the taxable wages on my W-2.  However, when I compare my "Social Security Wages" (Box 3)  to my "Wages, tips, other compensation" (Box 1), the difference is exactly the amount of my Roth 401k contribution listed in Box 12.  The codes in box 12 are AA (Roth contributions to 401k plan) and D (Elective deferrals to 401k). 

[dmertz · Accepted solution]

It's the code-D amount that should be excluded from the wages.  Did you split your contributions 50/50 such that the difference between box 1 and box 5 of your W-2 is equal to the amount reported with code D?  That would make sense.

[ThisIsSoTaxing]

Yes, that is exactly what happened!  This is not actually regarding my W-2.  I'm doing my daughter's taxes and I didn't realize she had split her contributions that way.  Thank you for your response!