How are 401k Contributions Reflected on a W-2?

Your 401k contributions must be reflected on your Form W-2 (if they are an employee deferral).  While your payroll company should be familiar with the process, here is a quick overview:

  • Box 1 (Wages) – Do not include any pre-tax contributions made under an employee deferral.  This would reduce the amount in Box 1 by the salary deferral.
  • Box 3 & 5 (Social Security and Medicare wages) – This should be the gross wages subject to employment taxes and does not consider any pre-tax, after-tax and or designated Roth contributions.
  • Box 12 (Codes) – Make sure to enter the appropriate code to show elective deferrals and designated Roth contributions. The codes differ depending on the type of contribution.
  • Box 13 – This box should be checked if you are an active participant in a retirement plan.
  • Box 14 (Other) – You can enter the amount of employer matching and nonelective contributions that are made to the plan and any voluntary after-tax contributions (not including Roth contributions).