What Is a 408(k) Plan?

The term 408(k) account refers to an employer-sponsored retirement savings plan. A 408(k) plan allows employees to put aside pretax dollars for retirement that grow on a tax-deferred basis, making it a type of individual retirement account (IRA). This means that individuals pay taxes when they make withdrawals after they turn 59½. The 408(k) is commonly referred to as a simplified employee pension (SEP) plan. In fact, it is the SEP version of the popular 401(k) plan.

Understanding 408(k) Plans

Section 408(k) of the Internal Revenue Code (IRC) outlines the rules and regulations associated with SEP and salary reduction simplified employee pension (SARSEP) accounts, notably individual retirement accounts (IRAs) or individual retirement annuities. That is why SEP plans are often referred to as 408(k) plans.

The IRC highlights the requirements needed in order to participate in a 408(k) plan. Plans are available to small businesses of any size and to self-employed individuals. Participants qualify if they are:

• Over the age of 21
• Worked for at least three of the last five years for the employer
• Were compensated at least $650 by the employer (for 2022; compensation requirements increase to $750 for 2023)
  

Annual employer contributions cannot exceed the lesser of 25% of the employee's pay or $61,000 for 2022 ($66,000 for 2023). The annual compensation limit cannot be calculated on incomes exceeding $305,000 for 2022 ($330,000 in 2023). The maximum deduction claimed on a business tax return for contributions is the lesser of the total contributions into employees' accounts or 25% of compensation.

Plan holders can make withdrawals from their 408(k) plans at any time—the same way they would from traditional IRAs. But there are certain conditions that apply. For instance, most individuals make withdrawals after they turn 59½. Any distributions from these plans before that age incur a 10% early withdrawal penalty. Withdrawals must be made as required minimum distributions (RMDs) as of April 1 the year after you turn 72 if you reached that age on or before Dec. 31, 2022. You must begin taking RMDs if you turn 73 on or after Jan. 1, 2023.

408(k) Plans vs. 401(k) Plans

As noted above, a 408(k) is one type of employer-sponsored retirement plan. The 401(k) plan is the most common option and is offered by the vast majority of American corporations. The plan allows taxpayers to make pre-tax contributions through automatic payroll deductions and employer matches for those that make them.

Plan reform has made several changes to benefit employees, including lower fees and investment options. The average 401(k) plan now offers over two dozen investment options by balancing risk and reward, in accordance with an employee's preferences. Unlike an SEP, employees may contribute to a 401(k) plan. A solo 401(k) plan is also available to self-employed individuals or couples, with the same total contribution limits as an employer-sponsored plan.

Participation in traditional 401(k) plans continues to grow. These plans held roughly $6.3 trillion in assets by September of 2022, which represented more than half of the retirement market in the United States. There were 625,000 active plans in the country with a total of 60 million former employees and retirees at the end of September 2022.

• Contribution limits for 401(k) plans are indexed to inflation. The Internal Revenue Service (IRS) allowed employees to save up to $20,500 for 2022, rising to $22,500 for 2023. Catch-up contributions of $6,500 per year (increasing to $7,500 in 2023) are also allowed for people 50 or older.
• Withdrawals before the age of 59½ often result in a 10% early withdrawal penalty, unless an exemption is applied. Taxes are imposed on any withdrawals made as contributions are made with pretax earnings.
• Individuals who turn 72 between Jan. 1, 2020, and Dec. 31, 2022, must begin taking RMDs the following April 1. The SECURE ACT 2.0 raised that age to 73 for anyone who turned that age on or after Jan. 1, 2023.

Correction—Jan. 27, 2023: A previous version of this article misstated that 408(k) plans are available to companies with 25 employees or less. It was corrected to state that plans are open to companies of any size.