The contribution amount was not excluded from my wages on line 1. Can I adjust the figure when I input my w2 info.

The contributions were not reflected on my w2 form. neither line 12 or line 1. Do I need to obtain a corrected w2?Thank you for your help.

The 401k plan is with my union hall not the employer themselves. We have had issues in the past with contributions being late. It has never been between two tax...