That is a very good question. I applaud you for understanding that there actually is a cost to participants for their 401(k). Unfortunately, too many participants think that this is free. Your HR department or plan administrator are supposed to provide this information to you. Starting this year, long-delayed Department of Labor regulations will be in effect that require this disclosure. It will be available on Form 5500 that has to be filed with the Department of Labor as well. At some point services like Judy Diamond, Larkspur and Brightscope will have this information available on their websites as well. But this will take two years probably. So your best bet is speaking with the HR or plan administrator first.