The average 401K account balance at the end of 1998 was $47,000 per participant, up 26% from 1996, according to the ICI and the Employee Benefit Research Institute. On average, 78% of eligible employees will participate in a 401(k) plan if one is made available, with the number of participants growing from 19.5 million in 1990 to 53.2 million in 2000. Some of the increase in participation rates is due to the introduction of "negative election," which allows an employer to automatically enroll employees into the 401(k) when they meet the plan’s eligibility requirements. The negative election deferral rate and investment(s) must be defined ahead of time, and the employee must be immediately notified of his or her participation status. Automatic enrollment programs are sanctioned by the IRS under ERISA as long as the employee has ample ability to cease enrollment at will.

US Securities Exchange Commission US Treasury: Small Business