How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask R. Klein, EA Your Own Question
R. Klein, EA
R. Klein, EA, Enrolled Agent
Category: Tax
Satisfied Customers: 3375
Experience:  Over 20 Years experience
Type Your Tax Question Here...
R. Klein, EA is online now
A new question is answered every 9 seconds

m helping out in our payroll dept, the payroll mgr is on Loa.

This answer was rated:

m helping out in our payroll dept, the payroll mgr is on Loa. employee said his w2 is incorrect from a previous year. how do I calculate it?
His 401k pretax and roth are wrong on his w2 I confirmed it with the 401k administrator. Im not sure how to recalculate it to provide him with a w2c
it's for 2008

Since the year is already closed, the only thing you can do is indicate on the W-2c the amount of the 401k contributions actually made. You can't go back and recompute the amounts based on percentages or anything like that. So the amount that was actually sent to the 401k company and taken out of his gross pay is the number that should appear in Box 12 of the W-2.


Was this a Roth 401K contribution or just a traditional 401k contribution? The only difference on the W-2 would be the code letter.


Do not take into account any company matches to the 401k. The only part that goes on the W-2 is the actual employee contribution amounts.


You may need to go through each paycheck and add up the deductions from each weekly or bi-weekly paycheck.




Customer: replied 5 years ago.
I've already spoken with the IRS they said I can sumbit a w2c
I have 30 days to do so and I have to send it to the ss office

I just don't know the calculations to get the correct figures

The company does not match with 401k.

It's just Roth contributions and pretax contributions

You will need to print out the employee's paycheck records for the year and add up the contributions deducted from the checks. Every paycheck created should have a breakdown of gross pay and all deductions.


There is no "calculation" other than that.


What calculations are you trying to find?



Customer: replied 5 years ago.
I'm trying to find the SS taxes for the w2, the IRS said it's off from some mag media they received

Social Security taxes are not affected by nor do they affect retirement account amounts.


However, in GENERAL,


Box 1 Wages = Gross Wages minus pretax 401k (but NOT Roth 401k contributions)

Box 2 Federal Tax WH = no formula. Based on tables

Box 3 SS Wages = Gross Wages no subtractions for 401k.

Box 4 SS Tax withheld = should be Exactly 6.2% of Box 3 but not more than $6,324

Box 5 Medicare Wages = Should be the same as Box 3

Box 6 Medicare Tax = Exactly 1.45% of Box 5


There are no other formulas for a W-2/paycheck calculation.


Box 1 Gross wages is reduced by a few other things, notably any pre-tax healthcare (Section 125). Boxes 3 and 5 are similarly affected.


However, Boxes 3,4,5, and 6 do not affect a taxpayer's tax return

AND Boxes 3,4,5 and 6 are supposed to mesh with Forms 941 sent in quarterly.




R. Klein, EA and other Tax Specialists are ready to help you