Look at the last statement they sent you... that gets you really close.

1. Look at the acount statement that you receive each quarter, or

2. Call the 401(k) plan administrator that runs the accoount for your company and ask.

I agree with ebaines

You should as noted be getting a quarterly report of the earnings along with year end statements.

But you can always check with the plan administrator.

I check mine online, ( my provider has it available)