W-2 Retention

I've tried to find the answer in every place I can think of (searching this site, the IRS site, etc.). Does anyone know how long you must maintain copies of W-2s? I would guess it's like 941s (4 years from date of filing), but want to make sure.
We have stuff from 1998!
We have stuff from 1998!
Comments
Under FLSA - 3 years after the rcord is made.
Under FICA - 4 years from the later of the tax due date or the payment date
Under FUTA - 4 years from the later of the tax due date or the payment date
and for Wage payments
Under the Equal Pay Act - 3 yeard from the date the record is made.
According to our company policy, we keep them for 7 years just to be on the safe side.