Understanding 401k Non-Discrimination Testing

If you’re a participant in a 401k plan, then you’re probably already aware of non-discrimination testing. This testing is an important part of ensuring that your 401k plan is compliant with regulations set forth by the Internal Revenue Service (IRS). The purpose of non-discrimination testing is to ensure that a plan does not favor highly compensated employees over non-highly compensated employees. In this article, we’ll take a closer look at what non-discrimination testing is and why it’s important.

Understanding 401k Non-Discrimination Testing

What is 401k Non-Discrimination Testing?

When employers offer a 401k plan, they must comply with rules established by the IRS that are designed to prevent discrimination in favor of highly compensated employees (HCEs). Non-discrimination testing refers to these rules and regulations that govern how contributions are made to a 401k account.

Non-discrimination testing compares contributions made to the accounts of HCEs versus those made to the accounts of non-highly compensated employees (NHCEs) and tracks who participates in the plan. This information helps ensure compliance with federal law, which requires plans to provide benefits fairly across all worker groups.

Why is Non-Discrimination Testing Important?

Non-discrimination testing is important because it helps ensure that all participants receive fair and equal treatment under their retirement benefits program. If an account fails non-discrimination testing, then it will become subject to additional taxes and may disqualify certain tax advantages for those contributing funds into those accounts. In extreme cases, it may result in having all deductions for the current year placed into refunds only, rather than future years or outright forfeiture.

Specifically, here are some reasons why you should care about non-discrimination testing:

It Prevents Discrimination

The main reason for conducting nondiscriminatory tests on your 401k plans is to avoid any discrimination based on compensation levels or job roles. Generally, highly compensated employees tend to have more disposable income than the non-highly compensated employees, making it easier for them to contribute more money to their 401k plans. As a result, if those contributions go unchecked, it could result in higher contributions by HCEs than NHCEs.

To avoid this issue, non-discrimination testing ensures that plan participants and investments are fairly distributed among all contributors regardless of level of compensation attained. This way, everyone gets an equal chance at contributing to a healthy retirement fund.

It Avoids Tax Implications

If your company’s 401k plan fails nondiscriminatory tests – which is when highly compensated workers contribute disproportionately more than others – it could lead to tax implications for both employers and employees. These taxes can be significant and can cause additional stress on top of what should already be a favorable financial planning instrument.

Administering these tests helps you avoid penalties related to the compliance regulations as well as tax consequences that may arise from these issues. You’ll also avoid putting your retirement savings in jeopardy due to unforeseen discrepancies with your accumulated funds.

It Maintains Eligibility

Non-discrimination testing is vital because any failure could cause the entire 401k plan to lose qualified status. This means that all participants’ contributions would become taxable income rather than sheltered from taxes through deductions.

The most important aspect of non-discrimination testing is maintaining eligibility for participation in a company’s 401k plan. When a plan loses its qualified status, it no longer meets specific criteria set forth by the IRS which makes the plan ineligible for certain benefits like matching contributions or other employer provided incentives geared towards helping employees save towards retirement.

The Two Types of Non-Discrimination Tests

There are two main types of non-discrimination tests that must be performed annually: (1) The Actual Deferral Percentage Test (ADP), and (2) The Actual Contribution Percentage Test (ACP).

Actual Deferral Percentage Test (ADP)

The ADP test is a measure of whether highly compensated employees have made contributions to the retirement plan disproportionately greater than that have been made by non-highly compensated employees. This test measures "deferrals," which are pre-tax contributions made directly from your paycheck. It helps ensure that everyone has an equal chance to save and invest for their retirement.

There are two parts to this test – the first part tests elective deferral contributions of HCEs and the second part looks at NHCEs’ deferral contributions. If average contribution rates of both groups fall within acceptable ranges, then the plan passes.

If HCEs contribute too much compared to NHCEs, there are steps that must be taken by plan administrators. The plan sponsor can either offer a refund in part or full on excess contributions made or make additional employer matching contributions to bring those averages closer together.

Actual Contribution Percentage Test (ACP)

The ACP test checks whether employer matching contributions have been proportionally distributed between HCEs and NHCEs. This test looks at any employer-match contribution, including profit sharing.

Again, if both groups’ contribution averages do not exceed certain percentages established by law, then the plan does pass this test. However, failing this may lead to required refunds of excess contribution amounts contributed by highly compensated employees.


Non-discrimination testing is an essential aspect of maintaining compliance with federal regulations for 401k plans while ensuring fair treatment among all workers eligible for participation. By administering these tests regularly, employers can rest assured knowing their plans are compliant while protecting participants’ retirement interests.

As a participant in your company’s 401k plan, you should have a basic understanding of how these tests work and what the implications could be if they fail. By doing so, you can better protect your retirement savings and work towards planning ahead successfully.


What is 401k non-discrimination testing?

401k non-discrimination testing is a requirement set by the IRS to ensure that retirement plans are benefiting all employees equally and not just highly compensated employees (HCEs).

Who needs to undergo 401k non-discrimination testing?

All companies with a 401k plan must undergo annual non-discrimination testing as mandated by the IRS.

What happens if the test fails?

If the test fails, corrective action must be taken to make sure that HCEs aren’t disproportionately benefitting from the plan. Otherwise, the plan could lose its tax-qualified status and face penalties.

How is eligibility for participation in a plan determined for non-discrimination testing purposes?

Eligibility for participation in a plan is determined according to various criteria, including service hours worked, age, and compensation received.

Can employee contributions affect non-discrimination test results?

Yes, employee contributions can affect non-discrimination test results since contribution limits can differ depending on an employee’s position within the company. This means that HCEs may be able to contribute more than their lower-compensated peers, leading to disproportionate benefits.

What are some common challenges faced during 401k non-discrimination testing?

Some common challenges include lack of understanding of complex regulations and schedules, difficulty tracking certain compensation types due to irregular pay cycles or bonuses, and confusion around eligibility requirements based on hours worked or job titles.

Is it possible to correct failed tests after they occur?

Yes, corrective actions can be taken after a failed test occurs through methods like returning excess contributions or implementing cross-tested designs that meet IRS guidelines. However, it’s best to avoid failing tests in the first place through proper planning and strategizing.

What should a company do to prepare for non-discrimination testing?

Companies should have a thorough understanding of the rules and regulations surrounding non-discrimination testing, keep accurate records of employee data, and work with experienced benefits professionals to develop effective strategies for meeting IRS guidelines.

Are there any exemptions from non-discrimination testing requirements?

Certain safe harbor plans are exempt from some or all non-discrimination testing requirements, but they must meet certain criteria, such as providing matching contributions to all employees or offering a set contribution percentage to all participants.

How does passing 401k non-discrimination testing benefit employees?

Passing non-discrimination testing helps ensure that all employees receive equal opportunities for retirement benefits regardless of their position within the company or compensation level. This promotes fairness and encourages employee engagement and loyalty.

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