How a Section 125 Cafeteria Plan Reduces Payroll Taxes for Mid-Size Employers

Every time an employee contributes to their health plan premiums out of their paycheck, both of you pay FICA taxes on that dollar before it ever reaches the carrier. That is 7.65 cents on every dollar lost to Social Security and Medicare, taken from your side as the employer and again from the employee's side, before a single medical claim is filed. The mechanism that eliminates this cost has existed in the tax code since 1978. It is called a Section 125 cafeteria plan, and it is one of the most straightforward ways a mid-size employer can reduce benefits costs without changing a single benefit.

Section 125 of the Internal Revenue Code lets employees elect to pay for qualifying benefits with pre-tax dollars rather than after-tax dollars. The result is a legal reduction in taxable wages for both parties. Employees pay no federal income tax, no FICA, and in most states no state income tax on those dollars. Employers pay no FICA on the contributions either. For a company with 50 employees each contributing an average of $4,800 per year toward their health plan premiums and a healthcare flexible spending account, the employer saves roughly $18,400 in annual FICA costs alone. The benefits do not change. The carrier does not change. The contribution amounts do not change. Only the tax treatment does.

Despite how clear the math is, many mid-size employers either run their pre-tax benefit elections without a proper Section 125 plan document in place, or have a document that was set up years ago and never reviewed. If you have never seen a line item on your benefits cost summary showing employer FICA savings from your plan structure, this guide walks through what a Section 125 cafeteria plan actually is, what it covers, what it saves, and what you need to have in place to use it correctly.

What Is a Section 125 Cafeteria Plan and How Does It Work

The Core Mechanism: Pre-Tax Benefit Elections

A Section 125 cafeteria plan is a written employer plan that gives employees the option to choose between cash compensation and a menu of qualifying tax-advantaged benefits. When an employee elects a qualifying benefit instead of taking that equivalent amount as taxable wages, the IRS excludes those elected amounts from the employee's gross income for federal income tax and FICA purposes.

The mechanism works through a salary reduction agreement. The employee agrees, before the plan year begins, to reduce their gross pay by the amount they want to direct to qualifying benefits. The employer withholds that amount before calculating income tax or FICA obligations. The result is a legally reduced taxable wage base for both parties. No money disappears. The same dollar that would have gone to the carrier via after-tax payroll deductions now goes to the carrier via pre-tax payroll deductions, and the tax savings flow back to both the employer and the employee.

Why It Is Called a Cafeteria Plan

The "cafeteria" name comes from the idea that employees pick from a menu of benefits, the way a diner picks from a cafeteria tray. Under the IRS rules, the plan must offer at least one taxable benefit (such as cash) alongside one or more qualified benefits. Most employers satisfy this requirement by offering the option to waive benefits and receive their premium contribution back as taxable pay. Employees who want the coverage elect it. Employees who waive can take the cash equivalent. Either way, the choice must be made before the plan year begins, and elections are generally irrevocable during the year except for qualifying life events such as marriage, birth, adoption, or a loss of other coverage.

For practical purposes, the vast majority of employer Section 125 plans are used to run health plan premium deductions on a pre-tax basis, to administer a healthcare flexible spending account, or both. The cafeteria structure is the legal container that makes those pre-tax deductions valid under federal law. Without it, you may be running pre-tax deductions operationally but without the legal backing that protects you in an audit.

How a Section 125 Cafeteria Plan Saves Money for Employers

The FICA Math: What Employers Save Per Employee

The employer FICA tax rate is 7.65 percent of each employee's taxable wages, covering 6.2 percent for Social Security (up to the annual wage base) and 1.45 percent for Medicare (with no wage cap). Every dollar of taxable wages removed from the calculation saves the employer 7.65 cents. That rate applies to both the employer's share and the employee's share, so the combined FICA reduction on one pre-tax dollar is 15.3 cents, split evenly between the two parties.

For an employee contributing $200 per month toward their health plan premiums, the employer saves about $184 per year in FICA on that one employee. That may not sound large in isolation. But multiply it across 50 employees at the same contribution level, and the employer saves roughly $9,200 per year in FICA alone, without touching the plan design, the carrier, or the benefit levels.

A Real-Number Example for a 50-Person Company

Consider an employer with 50 employees. The average employee contribution to health plan premiums is $3,600 per year. Thirty employees also elect a healthcare flexible spending account at an average of $1,200 per year. Here is how the Section 125 savings break down at the employer level:

• Health plan premium pre-tax savings: 50 employees x $3,600 x 7.65% = $13,770 per year
• Healthcare FSA pre-tax savings: 30 employees x $1,200 x 7.65% = $2,754 per year
• Total employer FICA savings: $16,524 per year

That $16,524 requires no changes to the plan, no changes to contributions, and no changes to what employees receive. The only requirement is a properly documented Section 125 cafeteria plan that makes the pre-tax elections legally valid. Employers who run premium deductions without a formal plan document in place are missing this savings entirely, and they are also exposing themselves to potential tax treatment disputes if payroll ever gets audited.

What Your Employees Save

Employees capture the same FICA savings on their side, plus a reduction in federal and state income taxes. For an employee in the 22 percent federal bracket, contributing $3,600 pre-tax to their health plan premiums saves them approximately $1,070 per year in combined taxes (22 percent income tax plus 7.65 percent FICA), in addition to any state income tax savings. That is a meaningful increase in take-home pay at no cost to the employer beyond setting up the plan correctly.

When employers can show employees this math during open enrollment, it becomes a tangible demonstration of the financial value of the benefits package. A $300 per month health plan contribution becomes roughly $215 per month in real out-of-pocket cost for an employee in the 22 percent bracket, once the tax savings are factored in. That framing changes how employees perceive the value of the benefit.

What Benefits Qualify for Section 125 Pre-Tax Treatment

Employer-Sponsored Health Plan Premiums

The most common use of a Section 125 plan is to run employee health plan premium contributions on a pre-tax basis. This applies to the employee's share of the premium for medical, dental, and vision coverage offered by the employer. The employer's contribution to the premium is already excluded from taxable wages without a Section 125 plan. The Section 125 plan is what makes the employee's contribution pre-tax as well.

This applies to any employer-sponsored group health plan, including fully insured plans, level-funded plans, self-funded plans, and plans offered through a professional employer organization. The funding structure of the health plan does not affect eligibility for pre-tax treatment. What matters is that the plan is employer-sponsored and that the employee is making a qualifying salary reduction election before the plan year begins.

Healthcare Flexible Spending Accounts

A healthcare flexible spending account, commonly called a health FSA, allows employees to set aside pre-tax dollars to pay for out-of-pocket medical expenses not covered by their health plan. Eligible expenses include copays, deductibles, prescription costs, vision care, dental work, and certain over-the-counter items. For 2026, the IRS annual contribution limit for employee health FSA elections is $3,300 per employee.¹

Health FSAs are employer-administered accounts. The employer must include FSA administration as part of its Section 125 plan document. Employees elect their annual FSA amount before the plan year starts, and the full elected amount is available on day one of the plan year, even though the payroll deductions come in gradually throughout the year. Plans may offer a grace period or a rollover provision (up to $660 in 2026) to reduce the "use it or lose it" pressure, but these are optional plan features rather than IRS requirements.

Dependent Care Flexible Spending Accounts

A dependent care FSA allows employees to set aside pre-tax dollars for qualifying child care and dependent care expenses, including daycare, preschool, before-school and after-school programs, and summer day camps. The annual limit is $5,000 per household for married employees filing jointly (or for single-parent households), and $2,500 for married employees filing separately.²

Dependent care FSAs are particularly valued by employees with young children. For mid-size employers competing for candidates with families, offering a dependent care FSA through a properly structured Section 125 plan is a low-cost benefit enhancement that directly addresses a real expense most working parents carry year-round. The employer saves FICA on every dollar elected, and the employee saves significantly on childcare costs that would otherwise be paid entirely with after-tax income.

Health Savings Account Contributions

Employees enrolled in a high-deductible health plan can contribute to a health savings account through payroll. When those HSA contributions are routed through a Section 125 cafeteria plan, they avoid both FICA and income taxes. For 2026, the IRS contribution limits are $4,300 for self-only coverage and $8,550 for family coverage.³

HSA contributions made directly by an individual (outside of payroll) still avoid income tax but do not avoid FICA. Running HSA contributions through a Section 125 payroll deduction structure captures that additional savings for both the employer and the employee. For an employee contributing $3,000 per year to their HSA through payroll, the FICA savings alone are over $200 per year compared to making the same contribution outside payroll. For more on how to structure employer and employee HSA contributions together, see our guide to employer HSA contributions for mid-size companies in 2026.

Setting Up a Section 125 Cafeteria Plan: What Employers Need to Know

The Written Plan Document Requirement

The IRS requires that a Section 125 cafeteria plan be set forth in a written plan document that meets specific content requirements under Treasury Regulation 1.125-1. The document must identify the eligible employees, describe the qualifying benefits offered, set the plan year, define the election procedures, and establish the rules for mid-year election changes. A verbal policy, an informal payroll practice, or a payroll provider's built-in pre-tax deduction setting does not substitute for a formal plan document.

This is where a significant number of mid-size employers have an undetected gap. Many payroll platforms make it operationally easy to deduct health premiums before taxes, and many employers assume that technical execution is sufficient. It is not. Without a compliant written plan document in place, the IRS can treat pre-tax deductions as if they were after-tax during an audit, triggering back taxes, penalties, and interest. The plan document must be adopted before the plan year for which it applies. Retroactive documentation is not permitted.

Plan documents can be obtained through a benefits attorney, a professional employer organization, or a benefits administration vendor. Many third-party administrators offer standardized Section 125 plan documents as part of FSA or health benefit administration services. For employers who already work with a PEO, the Section 125 plan is typically included in the PEO's master plan document, which also simplifies ongoing compliance administration. Our overview of dedicated-service PEOs vs. high-volume PEOs covers how these administrative differences show up in practice.

Annual Open Enrollment and Irrevocable Elections

Section 125 requires that employees make their benefit elections before the plan year begins, and those elections are generally irrevocable during the year. The IRS allows mid-year election changes only in response to qualifying life events: marriage, divorce, birth or adoption of a child, death of a dependent, a change in the spouse's employment or benefit eligibility, or a significant change in coverage costs. The specific list of permissible mid-year change events must be defined in the plan document and must align with IRS regulations.

For employers, this means open enrollment is not a formality. Employees who miss the election window or who elect the wrong FSA amount generally cannot change their elections until the next plan year. Employers who invest in clear open enrollment communication see higher FSA participation rates, fewer mid-year complaints about irrevocable elections, and more of the employer FICA savings that come from aggregate pre-tax contributions. Our guide to open enrollment strategy for mid-size employers covers how to structure the process for maximum informed participation.

Non-Discrimination Testing: The Requirement Most Employers Skip

Section 125 plans are subject to three annual non-discrimination tests: the eligibility test, the contributions and benefits test, and the key employee concentration test. The purpose of these tests is to ensure that the plan does not disproportionately benefit highly compensated employees (HCEs, generally employees earning over $135,000 in 2026) or key employees (officers or majority owners above certain ownership thresholds).

If a plan fails a non-discrimination test, the entire plan is not disqualified. Instead, the HCEs or key employees lose their pre-tax tax treatment for that plan year. Their elected benefits become taxable income, and the associated FICA savings disappear retroactively. Rank-and-file employees are unaffected.

Most mid-size employers with diverse employee populations pass these tests without difficulty. The risk is higher for companies with a small number of highly compensated employees and a large number of part-time or lower-wage workers where FSA participation is low. A benefits attorney or third-party administrator can run the three required tests annually, typically as part of FSA plan year-end administration. Employers who skip this step are exposed to a retroactive tax problem they may not discover until an audit.

Common Mistakes Mid-Size Employers Make With Pre-Tax Benefit Programs

Running Pre-Tax Deductions Without a Formal Plan Document

The most common mistake is also the most consequential. Many employers run health plan premium deductions through payroll on a pre-tax basis because their payroll provider's default setting does so automatically, without ever confirming that a written Section 125 plan document exists. From a payroll mechanics standpoint, the deductions look identical. From a tax compliance standpoint, the difference between a documented plan and an informal practice is the difference between a legal benefit and a tax exposure.

If your company has been running pre-tax health premium deductions for years, the first step is to confirm with your benefits attorney or PEO that a valid plan document exists, covers the current plan year, and has been properly adopted. If it does not, establishing one prospectively is straightforward. Attempting to retroactively document a plan that did not exist is more complicated and should involve legal counsel.

Skipping FSA Education During Open Enrollment

Employers who offer a healthcare FSA but provide minimal employee education during open enrollment typically see participation rates well below their potential. Low participation rates mean lower pre-tax contribution totals, which directly reduces the employer's FICA savings. An employer whose 50 employees could collectively elect $150,000 in FSA contributions, but where only 15 employees participate and elect an average of $800, is leaving about $5,000 per year in employer FICA savings unrealized, in addition to the individual tax savings employees are forgoing.

The most effective FSA communication during open enrollment shows employees the after-tax cost of typical out-of-pocket medical expenses versus the pre-tax cost, with a real dollar example based on their estimated bracket and planned election amount. Employees who see that a $2,000 dental expense costs them $1,400 to $1,600 out of an FSA versus $2,000 out of their checking account are more likely to elect meaningfully. That employee-level savings also represents employer FICA savings on every dollar elected.

Not Running the Annual Non-Discrimination Tests

The third common mistake is treating non-discrimination testing as optional. Many small and mid-size employers never run these tests, either because they are unaware of the requirement or because their benefits administrator does not include it as part of a standard service. If a test failure goes undetected for multiple years and is discovered in an IRS audit, the employer could face back FICA obligations for all the HCEs in the affected years, plus interest and penalties.

The annual cost of having a TPA run the three required tests is typically modest, ranging from a few hundred to a few thousand dollars depending on plan complexity and employee count. That cost is almost always justified by the FICA savings the plan generates in the first place, plus the protection it provides against retroactive tax exposure that compounds year over year.

Frequently Asked Questions

Do I need a Section 125 plan if my payroll provider already deducts health premiums before taxes?

Yes. The technical mechanics of a pre-tax deduction in payroll software do not substitute for a written Section 125 plan document. The IRS requires a formal written plan that meets specific content requirements under Treasury Regulation 1.125-1. If your company has been running pre-tax deductions without a plan document, you are getting the operational benefit but not the legal protection. An audit that uncovers the absence of a plan document can result in retroactive reclassification of those deductions as taxable wages, with associated taxes, interest, and penalties. Confirm with your benefits attorney or PEO that a valid plan document exists and covers your current plan year.

How much does it cost to set up and maintain a Section 125 cafeteria plan?

A basic Section 125 plan document from a benefits attorney or TPA typically costs between $500 and $1,500 to establish, with annual maintenance and non-discrimination testing fees in the range of $300 to $800 per year. Adding a healthcare FSA or dependent care FSA administration program typically runs $3 to $8 per employee per month depending on the TPA. For most mid-size employers, the employer FICA savings generated by a properly structured Section 125 plan cover the administrative costs many times over in the first year alone. Employers working with a PEO typically have Section 125 plan administration bundled into the PEO fee.

Can part-time employees be excluded from a Section 125 cafeteria plan?

Yes, with important limits. The IRS allows plans to exclude employees who work fewer than a specified number of hours per week (typically less than 17.5 hours), employees who have been employed fewer than a specified period (typically three months or less), and employees covered by a collective bargaining agreement. The exclusions must be stated in the plan document and applied consistently. Excluding part-time employees does not automatically cause a non-discrimination test failure, but plans that serve predominantly highly compensated employees while excluding most lower-wage workers are more likely to encounter issues in a non-discrimination analysis.

Can an employee change their FSA election mid-year if they overestimated their medical expenses?

Generally, no. FSA elections under a Section 125 plan are irrevocable for the plan year. The IRS allows mid-year changes only in response to specific qualifying life events, such as marriage, divorce, birth or adoption of a child, a change in employment status, or a significant change in the cost of dependent care. Overestimating medical expenses is not a qualifying event. Employees who discover mid-year that they elected too much can spend down their FSA on any eligible expense, including qualifying over-the-counter items, vision care, and dental work, to avoid forfeiting unused funds. This is why clear open enrollment education about realistic FSA election amounts reduces the problem significantly.

What happens if our Section 125 plan fails non-discrimination testing?

If the plan fails one of the three required tests, the affected group loses its pre-tax tax treatment for that plan year. For the eligibility test and the contributions and benefits test, it is the highly compensated employees who lose the pre-tax treatment. For the key employee concentration test, it is the key employees. Their elected benefits are treated as taxable income retroactively, and the employer owes FICA on those amounts for that year. Rank-and-file employees are not affected. The plan itself is not disqualified for everyone. The fix going forward is typically to redesign the plan to encourage broader participation among non-HCE employees, which brings the concentration ratios back into compliance. Running the tests annually catches failures before they accumulate into a multi-year problem.

Do we need a separate plan document for the FSA, or is it part of the Section 125 document?

The healthcare FSA and dependent care FSA are typically included within the same Section 125 cafeteria plan document, rather than maintained as separate stand-alone documents. The cafeteria plan document establishes the legal framework, and the FSA provisions are included as qualifying benefits available under the plan. Some employers also maintain a separate FSA summary plan description (SPD) that covers FSA-specific rules such as grace periods, rollover provisions, and claim filing deadlines. Both are required to be provided to employees. Your TPA or benefits attorney will typically provide both as part of the initial plan setup.

References

1. Internal Revenue Service. "Revenue Procedure 2025-19: 2026 Inflation-Adjusted Amounts for Health FSAs." Available at irs.gov.
2. Internal Revenue Service. "Publication 503: Child and Dependent Care Expenses, 2026." Available at irs.gov.
3. Internal Revenue Service. "Revenue Procedure 2025-19: 2026 HSA Contribution Limits and HDHP Thresholds." Available at irs.gov.
4. Society for Human Resource Management. "2024 Employee Benefits Survey: Prevalence and Participation in Flexible Spending Accounts." Available at shrm.org.
5. U.S. Department of the Treasury. "Treasury Regulation Section 1.125-1: Cafeteria Plan Requirements." Available at ecfr.gov.
6. Kaiser Family Foundation. "2024 Employer Health Benefits Survey: Employee Premium Contributions and Cost-Sharing." Available at kff.org.