New Jersey 401k basis

[Vince1972]

How to estimate lifetime 401k contributions to accounts where information is no longer accessible ?

[BillM223]

Do you have copies of old W-2s? The 401(k) contributions on old W-2s will be listed in box 12 with a code of D.

You can get some old tax records from the IRS by looking at the Transcript section. You probably want the Wage and income transcript, so that you can see your old W-2s. This may get you the W-2s for the last 9 or 10 years.