401(k) plans are IRS-sanctioned, tax-advantaged employee retirement savings plans offered by private, for-profit employers and some nonprofit employers. 401(k) plans are the most common type of defined contribution retirement plans.

457(b) plans are IRS-sanctioned, tax-advantaged employee retirement plans offered by state and local public employers and some nonprofit employers. They are one of the least common forms of defined contribution retirement plans.

Differences Between 401(k) and 457 Plans

401(k) plans are considered qualified retirement plans and are therefore subject to the Employee Retirement Income Security Act of 1974 (ERISA). 457 plans, however, are a type of tax-advantaged non-qualified retirement plan and are not governed by ERISA.

Since ERISA rules do not apply to 457 accounts, the IRS does not assess a "premature withdrawal" penalty to 457 participants who take withdrawals before age 59.5. The withdrawals are still subject to normal income taxes. Premature withdrawals from a 401(k) result in an additional 10% tax penalty.

457 plans feature a "Double Limit Catch-up" provision that 401(k) plans do not. This provision is designed to allow participants who are nearing retirement to compensate for years in which they did not contribute to the plan but were eligible to do so. Thus, under the right conditions, a 457 plan participant may be able to contribute as much as $35,000 to his plan in one year.

While both plans allow for early withdrawals, the qualifying circumstances for early withdrawal eligibility are different. Plan participants can make early withdrawals from a 401(k) under "financial hardships," which are defined by each 401(k) plan. With 457 accounts, hardship distributions are allowed after an "unforeseeable emergency," which must be specifically laid out in the plan's language.

Both public government 457 plans and nonprofit 457 plans allow independent contractors to participate. Independent contractors are not eligible to participate in 401(k) plans.

Similarities Between 401(k) and 457 Plans

As defined contribution plans, both 401(k) and 457 plans are funded when employees contribute through payroll deductions; participants of each plan set aside a percentage of their salary to put into their retirement account. These funds pass to the retirement account without being taxed, unless the participant opens a Roth account, and any subsequent growth in the accounts is not taxed.

As of 2014, both 401(k) and 457 plans have an annual maximum contribution limit of $17,500. For employees over the age of 50, both plans contain a "catch-up" provision that allows up to $5,500 in additional contributions. Contributions to each plan qualify the employee for a "Saver's Tax Credit." It is possible to take loans from both 401(k) and 457 plans.

Can You Contribute to 401(k) and 457 Plans Simultaneously?

Since 457 plans are nonqualified retirement plans, it is possible to contribute to both a 401(k) and 457 plan at the same time. Many large government employers offer both plans. In such cases, the joint participant is able to contribute maximum amounts to both.

The Advisor Insight

Both plans allow employees to save money for retirement by deducting from pre-tax income that employees contribute to the plan, which is then invested and taxed only upon withdrawal in retirement, at which point the retiree's ordinary income tax rate is applied. Since we have no active earnings in retirement, our ordinary income tax rate is generally very low compared to a much higher rate when we are still part of the workforce. Accordingly, the tax deferral associated with 401(k)s and 457 plans can provide meaningful tax savings. The key difference between the two pertains to distribution rules. 457 plans permit individuals to withdraw funds early without having to pay the 10% early withdrawal penalty imposed on 401(k) plan holders, but only in the event that they switch employers.

Emma Muhleman

Ascend Investment Partners

Grand Cayman, CA