There have been few ideas by Congress more popular than 401(k) Plans. In the 20 years since Congress invented the 401(k) Plan, over $1.7 trillion dollars have been deposited by employees. It is safe to say that essentially 100% of the employees in companies that do not offer 401(k) plans put pressure on their employers to start a plan. Employers pay the cost of starting and maintaining a plan and often provide matching contributions as well. In these plans, the enrollment is over 90% on average.