Section 125 nondiscrimination testing is the annual compliance step that protects the tax savings in a cafeteria plan. The IRS allows employees to pay for benefits with pre-tax dollars only if the plan treats lower-paid workers fairly compared to owners and executives. This guide explains the three tests, who counts as highly compensated, when testing happens, and what a failed test costs.
If you are new to cafeteria plans, start with our Section 125 cafeteria plan 2026 guide for the basics, then come back here for the testing rules.
What is Section 125 nondiscrimination testing?
Section 125 nondiscrimination testing is a set of IRS-required calculations that check whether a cafeteria plan favors highly compensated or key employees. The IRS requires the test because pre-tax benefits reduce federal income tax and FICA, and the government does not want that tax break to flow mostly to owners and executives. The test compares how much value highly compensated employees get from the plan against how much value everyone else gets.
A cafeteria plan is the only way employees can pay for benefits with pre-tax dollars under Internal Revenue Code Section 125 (IRS). Without a compliant plan, every premium dollar is taxed. Nondiscrimination testing is the price of admission for that tax treatment. The IRS spells out the rules in Section 125(b), (c), and (g), and in the proposed cafeteria plan regulations.
Testing applies to the plan as a whole and to specific benefits inside it. A premium only plan, a flexible spending account (FSA), and a dependent care account each have their own test rules. Most small and mid-size employers run all required tests at once through their plan administrator.
What are the three Section 125 nondiscrimination tests?
A standard cafeteria plan must pass three tests: the eligibility test, the contributions and benefits test, and the key employee concentration test. Each test looks at a different way a plan could tilt toward the top of the pay scale. A plan must pass all three to keep pre-tax treatment for highly compensated and key employees.
Here is what each test measures.
| Test | What it checks | Pass condition |
|---|---|---|
| Eligibility test | Whether enough non-highly-compensated employees can join the plan | Plan does not require excessive service or exclude too many lower-paid workers |
| Contributions and benefits test | Whether highly compensated employees get a larger share of pre-tax benefits | Benefits are available and used fairly across pay levels |
| Key employee concentration test | Whether key employees (mostly owners and officers) take more than 25% of total pre-tax benefits | Key employees receive 25% or less of all nontaxable plan benefits |
The 25% key employee rule is the one that trips up small businesses most often. In a 12-person company where the two owners and a spouse run most of their benefits through the plan, the owners can easily cross the 25% line. That is a math problem, not a paperwork problem, and it has to be solved during plan design.
Who counts as a highly compensated or key employee?
A highly compensated employee for cafeteria plan purposes is an officer, a more-than-5% owner, an employee earning above the IRS compensation threshold, or a spouse or dependent of any of those people. A key employee is generally an officer earning above a set dollar amount, a more-than-5% owner, or a more-than-1% owner earning above $150,000 (IRS). The exact dollar thresholds adjust most years, so confirm the current figures with the IRS or your plan administrator before testing.
These definitions matter because the tests compare this group against everyone else. The more compensation and ownership concentrate at the top, the harder the tests are to pass. A company with one owner and 40 employees on similar pay usually passes with room to spare. A company with three owners and six staff has to design the plan carefully.
When do you run nondiscrimination testing?
Cafeteria plan nondiscrimination testing is performed for each plan year, and the IRS expects the test to reflect the plan's actual operation during that year. Most employers run a projection test before the plan year begins, then a final test as of the last day of the plan year. The IRS does not require you to file the test results, but you must keep them on hand in case of an audit.
Running an early test matters. If you wait until year-end and discover a failure, the affected highly compensated employees owe tax on benefits they already elected, and you cannot undo a plan year that already happened. A projection test in the first month gives you time to adjust the plan design, change contribution structures, or expand eligibility before the failure becomes real.
For more on how the underlying FICA savings work, see our guide to maximizing FICA tax savings.
What happens if a Section 125 plan fails the test?
If a cafeteria plan fails nondiscrimination testing, the highly compensated or key employees lose pre-tax treatment for the plan year, and their elected benefit amounts become taxable income. The rank-and-file employees keep their pre-tax treatment in full. The penalty falls only on the favored group the test is designed to protect against, not on the whole workforce.
For a failed key employee test, the key employees must include the value of their nontaxable benefits in gross income for the plan year. That means back federal income tax and, in most cases, the loss of the FICA savings on those amounts. The employer also has to correct payroll records and issue updated W-2 figures for the affected people.
A failed test does not shut down the plan. It does not make benefits taxable for regular employees. It is a targeted correction, and a well-designed plan with annual testing almost never reaches that point.
How do employers avoid a failed test?
Employers avoid failed tests by designing the plan around their real payroll and ownership data before the year starts. The most common fixes are broadening eligibility so more lower-paid employees can join, adjusting how owner and executive benefits run through the plan, and using a safe plan structure that limits key employee concentration. A premium only plan, where employees simply pay their share of insurance premiums pre-tax, has simpler testing than a full FSA-based plan.
Three practical steps lower your risk:
- Run a projection test in the first month of the plan year using current payroll.
- Keep eligibility broad so non-highly-compensated employees can participate.
- Review owner and family member elections, since these drive the 25% key employee calculation.
Small employers with concentrated ownership benefit most from professional plan design. The savings from a Section 125 plan are real, but only if the plan passes its tests. Our guide to why Section 125 reduces W-2 wages shows how the pre-tax mechanics work once the plan is compliant.
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Frequently Asked Questions
Is Section 125 nondiscrimination testing required every year?
What are the three Section 125 nondiscrimination tests?
Who is a highly compensated employee for a cafeteria plan?
What happens if my Section 125 plan fails the test?
Does a failed test affect all employees?
Why do small businesses fail the key employee test most often?
Does a premium only plan still need testing?
When should I run nondiscrimination testing?
Summit Health Benefits sets up compliant Section 125 plans with annual nondiscrimination testing included, so you keep your tax savings without the audit risk.
Set up a compliant planSources
Internal Revenue Code Section 125(b), (c), and (g) and the IRS proposed cafeteria plan regulations (Internal Revenue Service); IRS rules on highly compensated and key employee definitions (Internal Revenue Service). Confirm current-year dollar thresholds with the IRS before testing.