What Does S125 on Your W-2 Mean? If you opened your 2025 W-2 form this tax season and spotted “S125,” “SEC 125,” “CAF,” or “CAFE” in Box 14, you’re probably wondering what it means for your taxes. The good news? It’s not a tax, penalty, or hidden deduction—it’s actually one of the smartest ways employers help you lower your taxable income.
S125 on your W-2 refers to pre-tax contributions you made through a Section 125 cafeteria plan (also called a flexible benefits or premium-only plan). These amounts were already subtracted from your gross pay before federal income tax, Social Security, and Medicare taxes were calculated. As a result, your Box 1 wages (and usually Boxes 3 and 5) are lower, putting real money back in your pocket.
In this complete guide tailored for U.S. employees and families, we’ll break down exactly what S125 means, how it works, the tax benefits, current contribution limits, and what (if anything) you need to do when filing your 2025 taxes.
What Is a Section 125 Cafeteria Plan?
Section 125 of the Internal Revenue Code lets employers offer employees a choice between cash (taxable wages) and certain qualified benefits paid with pre-tax dollars. This is why it’s nicknamed a “cafeteria plan”—you pick the benefits that fit your life.
Common qualified benefits under a Section 125 plan include:
- Health, dental, and vision insurance premiums
- Health Flexible Spending Accounts (Health FSAs)
- Dependent Care Flexible Spending Accounts (Dependent Care FSAs)
- Certain other benefits like adoption assistance (reported differently)
These contributions reduce your taxable wages right from your paycheck, so you pay less in federal income tax, Social Security (6.2%), and Medicare (1.45%) taxes—saving you 22–37% or more depending on your tax bracket.
Important note for 2026 filers: Your 2025 W-2 reflects the 2025 plan year rules. New higher limits apply starting in 2026 (more on that below).
Where Does S125 Show Up on Your W-2?
- Box 14 (Other): This is where most employers voluntarily list the total S125 amount. It’s purely informational—you don’t add or subtract it anywhere on your Form 1040.
- Box 1 (Wages, tips, other compensation): Already reduced by your S125 contributions.
- Boxes 3 and 5 (Social Security and Medicare wages): Usually reduced as well (subject to plan rules).
- Box 10 (Dependent care benefits): If you used a Dependent Care FSA, the total benefits appear here (up to the exclusion limit). Amounts over the limit are added back to Box 1 as taxable income.
Pro tip: S125 is not the same as Code DD in Box 12 (which reports the cost of employer-sponsored health coverage under the Affordable Care Act). They are separate reporting requirements.
How Much Can You Save with S125? Real Tax Benefits
By using pre-tax dollars, you avoid:
- Federal income tax (up to 37%)
- Social Security and Medicare taxes (7.65% combined for employees)
- State income tax (in most states)
Example: If you contributed $3,000 to a Health FSA or health premiums in 2025 and you’re in the 24% federal bracket + 7.65% FICA, you saved roughly $950 in taxes—money that stays in your pocket instead of going to the IRS.
Employers also save on their share of FICA taxes, which is why most companies with group health plans offer Section 125.
2025 vs. 2026 Section 125 Contribution Limits (What You Need to Know Now)
For your 2025 W-2 (filed in 2026):
- Health FSA salary reduction limit: $3,300 (plus up to $660 carryover from prior year if your plan allows)
- Dependent Care FSA exclusion limit: $5,000 ($2,500 if married filing separately)
Starting in 2026 plan year (affecting your 2026 W-2 next year):
- Health FSA limit increases to $3,400 (+ $680 carryover)
- Dependent Care FSA limit rises significantly to $7,500 ($3,750 if married filing separately) under recent legislation.
These limits are per employee (or per household for dependent care). Always check your plan documents—some employers set lower limits.
Use-it-or-lose-it rule: Health and Dependent Care FSAs generally require you to use funds by the plan’s deadline (or carry over a small amount if allowed). Plan your expenses carefully.
Do You Need to Report S125 on Your Tax Return?
Usually, no action is required.
- The pre-tax treatment is already reflected in your lower Box 1 wages.
- TurboTax and other software automatically handle Box 14 entries as informational only.
Exceptions:
- If you have amounts in Box 10 (Dependent Care FSA) over $5,000, the excess is taxable and already included in Box 1.
- Use Form 2441 (Child and Dependent Care Expenses) to claim the Child and Dependent Care Credit if eligible.
- Always keep your pay stubs and plan statements in case of an audit.
Frequently Asked Questions About S125 on W-2
- Is S125 a tax?
No—it represents tax savings. It shows money you didn’t pay taxes on. - Why does my employer show it in Box 14?
It’s optional but helpful for transparency so you can see your total pre-tax benefit usage. - Can I have S125 if I’m self-employed?
No—Section 125 plans are employer-sponsored only. Self-employed individuals use other options like HSAs or self-employed health insurance deductions. - What if I didn’t use all my FSA funds?
You may forfeit unused amounts (subject to your plan’s grace period or carryover rules). - Does S125 affect my state taxes?
In most states, yes—the pre-tax treatment flows through. A few states don’t conform; check your state tax instructions.
Bottom Line: S125 Is One of the Best-Kept Secrets for Lowering Your Tax Bill
Seeing S125 on your W-2 is a sign that your employer is helping you keep more of your hard-earned money through smart pre-tax benefits. Whether you used it for health premiums, medical expenses, or childcare, you’ve already enjoyed lower taxable income and payroll taxes.
Action steps for 2026:
- Review your 2025 W-2 Box 14 and compare it to your year-end pay stub.
- Enroll promptly for 2026 benefits to take advantage of the new higher limits.
- Consult a tax professional or use trusted software like TurboTax if your situation includes dependent care, HSAs, or complex benefits.
- Talk to your HR department about maximizing your Section 125 options.
For the most accurate, up-to-date guidance, always refer to official IRS resources such as the General Instructions for Forms W-2 and W-3 and Publication 969 (Health Savings Accounts and Other Tax-Favored Health Plans).
Filing your taxes doesn’t have to be stressful. Understanding codes like S125 puts you in control—and helps you keep more money where it belongs: in your wallet.
This article is for informational purposes only and is not tax advice. Tax laws can change, and your situation may vary. Consult a qualified tax professional or the IRS for personalized guidance.