Section 125 Cafeteria Plans: Pre-Tax Rules, FSAs, and Elections

A Section 125 cafeteria plan is an employer-sponsored arrangement that lets you pay for health insurance premiums and certain other qualified benefits with pre-tax dollars, lowering both your federal income tax and the 7.65% FICA tax on every dollar you redirect into coverage. The name comes from the menu structure: you choose between taxable cash (your regular paycheck) and qualified non-taxable benefits like medical insurance or a flexible spending account. For most workers, that shift is worth hundreds or thousands of dollars a year.

How the Pre-Tax Deduction Works

You sign a salary reduction agreement authorizing your employer to subtract benefit premiums from your gross pay before calculating taxes. Because your taxable wages drop, you pay less in federal income tax, Social Security tax (6.2%), and Medicare tax (1.45%). Your employer saves on its matching 6.2% Social Security and 1.45% Medicare contributions on the same amount.¹

A quick example. Say you earn $4,000 a month and direct $500 toward health premiums through the plan. Your taxable wages drop to $3,500. If you sit in the 22% federal bracket, that $500 pre-tax deduction saves roughly $110 in income tax plus about $38 in FICA each month. Over a year, that is around $1,776 in tax savings on premiums you would be paying anyway. Actual savings depend on your bracket and whether your state also exempts cafeteria plan contributions from income tax; most do, a handful do not.

What You Can Pay For Pre-Tax

Not everything qualifies. The IRS limits pre-tax treatment to a specific list of benefits:²

Health insurance premiums, including medical, dental, and vision coverage. This is the most common use.
Health flexible spending accounts (FSAs). For 2026, you can contribute up to $3,400 for out-of-pocket medical expenses like copays, prescriptions, and eyeglasses.
Dependent care assistance. Beginning in 2026, the annual household limit rises to $7,500 ($3,750 if married filing separately), up from the previous $5,000 cap.³
Group-term life insurance up to $50,000 in coverage is fully exempt from income tax. Coverage above $50,000 stays exempt from income tax withholding but becomes subject to Social Security and Medicare taxes.
Health savings account (HSA) contributions, but only if you are enrolled in a qualifying high-deductible health plan. A general-purpose health FSA disqualifies you from HSA contributions in the same year; a limited-purpose FSA covering only dental and vision is the workaround.
Adoption assistance provided by the employer.

Commuter and parking benefits, educational assistance, and long-term care insurance do not qualify for cafeteria plan treatment. Disability premiums can go through the plan, but there is a catch: if you pay them pre-tax, any disability benefits you later receive become taxable income. Many employees deliberately pay disability premiums with after-tax dollars to keep future benefit payments tax-free.

Who Can Participate

Common-law employees, both full-time and part-time, are eligible as defined in the employer’s plan document.⁴ Nearly any employer can set up a plan, including corporations, nonprofits, and government entities.

The main exclusions target business owners. Self-employed individuals, sole proprietors, partners in a partnership, and shareholders who own more than 2% of an S-corporation cannot participate in their company’s cafeteria plan.⁵ Congress drew this line to keep the tax break focused on rank-and-file workers rather than people who control their own compensation. If you fall into one of these categories, you can still deduct health insurance costs, but through different provisions of the tax code.

Your Election Locks In for the Year

Once you make your cafeteria plan elections, they are fixed. This irrevocability rule is the backbone of Section 125: the IRS grants the tax benefit precisely because you have committed to the deduction for the full plan year.⁶

The exception is a qualifying life event. Federal regulations allow (but do not require) your employer’s plan to permit mid-year changes when specific circumstances shift. The qualifying events include:

Change in marital status: marriage, divorce, legal separation, annulment, or death of a spouse.
Change in the number of dependents: birth, adoption, placement for adoption, or death of a dependent.
Change in employment status for you, your spouse, or a dependent that affects benefit eligibility.
A dependent aging out of coverage or gaining eligibility through another event.
A move that puts you outside your plan’s service area.
Gaining or losing Medicare or Medicaid eligibility.
A qualified medical child support order requiring coverage for a child.

Your election change has to be consistent with the event. Getting married lets you add your spouse to your health plan; it does not let you drop dental coverage just because you feel like it. And your employer decides which of these permitted changes to recognize. Some plans allow all of them; others limit the list. Check your plan document or ask your benefits administrator before assuming you can make a change.⁶

FSA Rules Worth Knowing Before You Enroll

Health FSAs have three rules that trip people up. Get them straight before you commit to a contribution amount.

Use It or Lose It

Any FSA balance left at the end of the plan year is forfeited unless your employer builds in a safety valve.⁷ Your plan may offer a grace period of up to two and a half months after the plan year ends to spend down your balance. Or it may allow you to carry over up to $680 in unused funds into the following year. A plan can offer one or the other, never both.⁸ Check which applies to your plan before deciding how much to contribute.

Your Full Election Is Available on Day One

This rule works in your favor. Your entire annual FSA election is available on the first day of the plan year, regardless of how much you have actually contributed through payroll deductions. If you elect $3,400 for the year and incur a $3,000 medical expense in January, the plan must reimburse the full $3,000.⁹ If you then leave the company in February, the employer cannot recover the difference between what it reimbursed and what you had contributed.

Leaving Your Job

Unused FSA funds are forfeited when your employment ends.¹⁰ COBRA continuation technically applies to health FSAs, but only when you have a positive balance and only for the remainder of the current plan year. In practice, electing COBRA for an FSA rarely makes financial sense: you would be paying the full contribution with after-tax dollars plus an administrative fee, without the tax benefit that made the FSA attractive to begin with. If you know you are leaving, spend the balance on eligible expenses before your last day.

The Social Security Trade-Off

Every dollar you redirect through a cafeteria plan reduces your FICA-taxable wages, and that is not just a current-year story. Social Security retirement benefits are calculated on your highest 35 years of earnings, and amounts excluded from wages through a Section 125 salary reduction do not count toward your earnings record.¹¹

For most people, the immediate tax savings outweigh the small reduction in future Social Security benefits. The effect matters most for lower-income workers, whose Social Security replacement rate is higher, or for anyone sitting near a bend point in the benefit formula. If you are already earning above the Social Security wage base ($176,100 for 2025), the pre-tax deduction does not affect your Social Security earnings record at all, because wages above that cap were not generating credits anyway.

What Your Employer Has to Have in Place

A cafeteria plan must exist as a formal written document. This is not a technicality; the entire tax benefit depends on it.⁴ The document must describe all benefits offered, eligibility rules, and procedures for making elections.² Without a valid written plan, the IRS does not recognize the arrangement as a cafeteria plan at all, and every dollar employees directed toward benefits gets reclassified as taxable income.¹² The same result applies when a valid document exists but the employer does not operate the plan according to its terms.

The law also requires annual nondiscrimination testing to make sure the plan does not disproportionately benefit highly compensated employees. For 2026 testing, a highly compensated employee is someone who earned more than $160,000 in the prior year.¹³ If testing fails, the highly compensated employees lose their tax-free treatment; rank-and-file employees keep their tax benefits regardless.⁴

Small employers can sidestep the testing under a “simple cafeteria plan” safe harbor in Section 125(j). To qualify, the employer must have averaged 100 or fewer employees during either of the two preceding years, and it must make all employees with at least 1,000 hours of service in the prior year eligible to participate (with limited exclusions for younger workers, new hires, collective bargaining employees, and certain nonresident aliens). The trade-off is a mandatory employer contribution: either a uniform 2% of each non-highly-compensated employee’s compensation, or a match equal to the lesser of 6% of compensation or twice the employee’s own salary reduction.¹⁴ A business that crosses 100 employees can keep using the simple plan structure up to 200 employees.

1
Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates
2
Internal Revenue Service. FAQs for Government Entities Regarding Cafeteria Plans
3
Office of the Law Revision Counsel. 26 USC 129 – Dependent Care Assistance Programs
4
Office of the Law Revision Counsel. 26 USC 125 – Cafeteria Plans
5
Internal Revenue Service. S Corporation Compensation and Medical Insurance Issues
6
eCFR. 26 CFR 1.125-4 – Permitted Election Changes
7
Internal Revenue Service. Publication 969, Health Savings Accounts and Other Tax-Favored Health Plans
8
Internal Revenue Service. Notice 2020-33 – Health Flexible Spending Arrangements
9
Internal Revenue Service. Health FSA Uniform Coverage Rules – Chief Counsel Advice 201012060
10
Internal Revenue Service. Notice 2013-71 – Modification of Use-or-Lose Rule
11
Social Security Administration. SI 00820.102 – Cafeteria Benefit Plans
12
Internal Revenue Service. Internal Revenue Bulletin 2007-39
13
Internal Revenue Service. Notice 2025-67 – 2026 Cost-of-Living Adjustments
14
Office of the Law Revision Counsel. 26 USC 125 – Cafeteria Plans – Section: Simple Cafeteria Plans for Small Businesses