Fidelity says 168,000 had $1 million or more in their 401(k) this spring -- up 50,000 from last year.
Fidelity's Jeanie Thompson says it's hard work, but you can do it.
"You know, when the 401(k) first came about I don't think anyone ever anticipated you could get to a million in it, but you can and that number has increased," she explains.
Thompson says these millionaires started saving early and really buckled down.
"On average these 401(k) millionaires save, on their own, about 15 percent of their pay and then take full advantage of any comparing match or profit sharing."
This has to be the message for your children: save, save and save.
"I would say it's very much a marathon and not a sprint," says Thompson. "The people that have achieved a million dollars in their 401(k) have done it over a 25- or 30-year career and they started young and they invested for growth; on average they hold about 75 percent in equities."
Thompson says the good news is you don't have to make a million to have a million in your 401(k). She says those who earn $150,000 can do it if they're smart.