Excerpt: Hewitt's study, which examined the saving and investment behavior of more than 2.5 million employees eligible for 401(k) plans, shows that the rate of participation in 401(k) plans during 2004 increased 2.1% to 70.3% from 2002, and average 401(k) balances reached $69,000. However, nearly 30% of employees still did not participate in their 401(k) plans, with only 46% of workers under the age of 30 participating.