What Is IRC 125 on W-2: Boxes Affected, Wages, and FSA Rules

If you see “IRC 125,” “Sec 125,” or “Cafe 125” on your W-2, it’s a reference to a cafeteria plan under Section 125 of the Internal Revenue Code, which is how your employer runs pre-tax deductions for benefits like health insurance premiums and flexible spending accounts. The label itself is informational. The tax effect has already happened: the amounts you elected were pulled from your pay before federal income tax, Social Security tax, and Medicare tax were calculated, and the wages reported on your W-2 are already reduced to reflect that.1Office of the Law Revision Counsel. 26 U.S. Code 125 – Cafeteria Plans

What Section 125 Means When You See It on Your W-2

A cafeteria plan is the arrangement the tax code uses to let you pay for certain benefits with pre-tax dollars instead of after-tax dollars. You pick the benefits during open enrollment, your employer subtracts the cost from your gross pay each period, and those dollars never show up as taxable wages. This is the only mechanism the tax code allows for paying employer-sponsored benefits pre-tax.2Internal Revenue Service. FAQs for Government Entities Regarding Cafeteria Plans

When employers write “Section 125,” “Sec 125,” “Cafe 125,” or “IRC 125” on the W-2, they’re just flagging which of your deductions ran through that plan. You don’t report the number anywhere on your tax return, and you don’t add it back to your income. The reduction is already baked into the wage boxes.

Which W-2 Boxes Section 125 Affects

Section 125 elections don’t get a single dedicated line. They ripple through several boxes at once.

Boxes 1, 3, and 5

Box 1 (federal taxable wages), Box 3 (Social Security wages), and Box 5 (Medicare wages) all reflect your pay after cafeteria plan deductions have been subtracted. If your gross compensation was $70,000 and you had $8,000 in pre-tax benefit deductions, expect roughly $62,000 in these boxes rather than $70,000. The three won’t always match each other exactly, because certain benefits get different FICA treatment and Box 3 is capped at the Social Security wage base ($176,100 for 2026).

Box 10

Dependent Care FSA contributions land in Box 10, whether or not you spent the money. You then reconcile the amount on IRS Form 2441 when you file, calculating how much of the benefit you can actually exclude from income.3Internal Revenue Service. Instructions for Form 2441 Anything over the statutory limit or over your earned income gets added back to taxable wages.

Box 12

Two Box 12 codes come up often with cafeteria plans:

  • Code W reports all Health Savings Account contributions made through the plan, including your pre-tax payroll deductions and any employer contribution. If you contributed $3,000 and your employer added $1,000, Code W shows $4,000.4Internal Revenue Service. 2026 General Instructions for Forms W-2 and W-3
  • Code DD reports the total cost of your employer-sponsored health coverage, combining your share and your employer’s share. It’s an Affordable Care Act reporting requirement, not taxable income. The number often looks large because it includes what your employer pays on your behalf.5Internal Revenue Service. Reporting Employer-Provided Health Coverage on Form W-2

Box 14

Box 14 is an optional space where employers can add notes. This is where labels like “Sec 125,” “Cafe 125,” or “FSA” typically appear, usually with a dollar amount next to them. The entry is informational only. Your tax liability is already determined by Boxes 1, 3, and 5.

Why Your Wages Look Lower Than Your Salary

The gap between your stated salary and the wages printed on your W-2 is usually explained by Section 125 deductions. Every dollar you routed through the cafeteria plan skipped three taxes at once for most benefits: federal income tax, the 6.2% Social Security tax, and the 1.45% Medicare tax. Your employer’s matching share of FICA also drops, which is part of why employers encourage enrollment.

The dollars come out of your pay either way; the question is whether they come out before or after taxes. Section 125 makes them pre-tax.

What Counts as a Section 125 Benefit

The most common cafeteria plan setup is a premium-only plan, where your share of health, dental, and vision insurance premiums comes out pre-tax. Beyond premiums, plans typically offer:

  • A Health FSA for medical expenses your insurance doesn’t fully cover, including deductibles, copayments, prescriptions, and certain over-the-counter items. The 2026 contribution limit is $3,400, and your full annual election is available from the start of the plan year.
  • A Dependent Care FSA for care of a child under 13 or a dependent who can’t care for themselves, so that you and your spouse can work. The 2026 limit is $7,500 per household for joint and single filers, or $3,750 if married filing separately, raised from the long-standing $5,000 cap by the One Big Beautiful Bill Act effective January 1, 2026. The new $7,500 cap is not indexed for inflation.6Office of the Law Revision Counsel. 26 U.S. Code 129 – Dependent Care Assistance Programs
  • Health Savings Account contributions, if you’re in a high-deductible health plan. The 2026 HSA limits are $4,400 for self-only coverage and $8,750 for family coverage. HSA balances roll over indefinitely and belong to you if you change jobs.7Internal Revenue Service. Revenue Procedure 2025-19
  • Adoption assistance and group-term life insurance coverage.2Internal Revenue Service. FAQs for Government Entities Regarding Cafeteria Plans

Two things cannot go through a cafeteria plan, no matter how it’s structured: deferred compensation such as 401(k) contributions, which have their own tax rules, and long-term care insurance.1Office of the Law Revision Counsel. 26 U.S. Code 125 – Cafeteria Plans

The Social Security Trade-Off

Every dollar that reduces your Box 3 wages is a dollar the Social Security Administration doesn’t count toward your lifetime earnings record. Social Security retirement benefits are calculated from your highest 35 years of earnings, so consistently lower reported wages can slightly reduce your monthly benefit in retirement. The effect is usually small. For most workers the current-year tax savings outweigh a modest reduction in future benefits.

The trade-off matters more for workers whose earnings sit near the amount needed to qualify for Social Security credits, or near the bend points in the benefit formula where lower earnings have a proportionally larger impact. If you’re a high earner already above the Social Security wage base, cafeteria plan deductions don’t affect your Social Security calculation, because you’ve already hit the taxable maximum.

When You Can Change Your Election

Your Section 125 elections are locked for the plan year once open enrollment closes. You can only change them mid-year if a qualifying event happens, and the change has to be consistent with that event.8eCFR. 26 CFR 1.125-4 – Permitted Election Changes Qualifying events include:

  • A change in marital status, such as marriage, divorce, legal separation, annulment, or the death of a spouse.
  • A change in the number of dependents through birth, adoption, placement for adoption, or death.
  • A change in employment status for you, your spouse, or a dependent, including starting or leaving a job, unpaid leave, a shift between part-time and full-time, or a worksite change that affects eligibility.
  • A change in dependent eligibility, such as a child aging out of coverage or losing student status.

The consistency rule is strict. Having a baby lets you add the child to your health plan and increase your Dependent Care FSA. It doesn’t let you drop dental coverage that has nothing to do with the new dependent. Changes must be prospective, and most plans give you 30 to 60 days from the event to submit the change. Miss the window and you wait until open enrollment.

Watch the FSA Deadline

Money left in a Health FSA or Dependent Care FSA at the end of the plan year is forfeited. That’s the use-it-or-lose-it rule. For a Health FSA, your plan may offer one of two relief options, but never both:9Internal Revenue Service. Section 125 Cafeteria Plans – Modification of Permissive Carryover Rule

  • A grace period extending the deadline by up to two months and 15 days into the next plan year. For a calendar-year plan, that’s March 15.
  • A carryover of up to $680 of unused Health FSA funds into the following plan year for 2026. Anything above $680 is still forfeited.

Dependent Care FSAs follow their own rules and may include a grace period but have no carryover option. If your plan year is ending with money left in the account, look for eligible expenses you’ve been paying out of pocket, such as prescription sunglasses, contact lens solution, or an outstanding dental bill.

State Tax Differences

Federal treatment of Section 125 deductions is uniform, but a handful of states don’t fully conform. New Jersey, for example, generally taxes employee contributions to Health FSAs and other cafeteria plan benefits at the state level even though those contributions are pre-tax federally. If you live in a non-conforming state, your state wages on the W-2 may be higher than the federal Box 1 wages, and the difference is usually the Section 125 amount added back. Compare the federal and state wage lines to see how your state handles it.