What Is Sec 125 on a W-2? What It Means for Your Pay and Your Taxes

• Employee payroll tax is 7.65%, which is 6.2% Social Security plus 1.45% Medicare, so each $1,000 paid through Sec 125 saves $76.50 in payroll tax, per the Social Security Administration (2026).
• The Social Security part applies only to the first $184,500 of wages in 2026, so above that wage level only the 1.45% Medicare saving applies, per the Social Security Administration (2026).
• The 2026 health FSA salary reduction limit is $3,400, per IRS Publication 15-B (2026).
• Workers paid an average of $1,440 a year for single coverage and $6,850 for family coverage in 2025, per the KFF Employer Health Benefits Survey (2025).
• A Sec 125 total lowers Box 1, Box 3 and Box 5 wages by the same dollar amount, per IRS Publication 15-B (2026).

You are reading a W-2 or a pay stub and you see "Sec 125" next to a dollar amount. Sec 125 means money was taken from your pay before tax through your employer's Section 125 cafeteria plan, and that lowers your taxable wages. It is a tax break, not a charge. The rest of this page shows where it appears, what it saves, and the few cases where you should ask a question.

Reviewed by a licensed benefits professional. Last reviewed: October 2, 2026.

What is Sec 125 on a W-2?

Sec 125 on a W-2 is shorthand for Section 125 of the Internal Revenue Code, which governs cafeteria plans. A cafeteria plan is a written employer plan that lets you choose between cash pay and certain benefits.

IRS Publication 15-B (2026) says that when an employee chooses a qualified benefit under the plan, the fact that cash was available instead does not make the benefit taxable. In plain terms, the premium comes out of your pay first and tax is figured on what is left.

Common benefits paid this way are health, dental and vision premiums and a health FSA. Benecor Health's Section 125 cafeteria plan guide→ explains how employers set one up.

What does sec 125 mean on my W-2?

Sec 125 on your W-2 means your Box 1, Box 3 and Box 5 wages are lower than your gross pay by your pre-tax benefit total. The label itself is not a printed W-2 line. It comes from your employer's payroll system.

The IRS W-2 and W-3 General Instructions (2026) require employers to report the cost of employer-sponsored health coverage in Box 12 with code DD. Box 14a is the W-2's "Other" box, and what an employer puts there varies. That is why your W-2 may show a Sec 125 total while a coworker's W-2 at another company shows none.

For the Box 14 label itself, read Benecor's guide to W-2 Box 14 and Section 125→. For Box 12, see what code DD means→.

Is sec 125 on my W-2 good or bad?

Sec 125 on your W-2 is usually good, because it means you paid for benefits with pre-tax dollars. It is a problem only if the amount is wrong or you never chose the plan behind it.

Benecor's guide to Sec 125 on the employee W-2→ covers more examples of what employees find on their forms.

How much does sec 125 on a W-2 save me?

Sec 125 saves you 7.65% in payroll tax on every dollar, plus income tax at your bracket. The Social Security Administration (2026) sets employee Social Security tax at 6.2% and Medicare tax at 1.45%.

Here is a worked example. It is hypothetical and uses 2026 payroll rates. A worker earns $52,000 and elects $240 a month for medical premiums, $30 a month for dental and a $1,200 health FSA.

1. Medical: $240 x 12 = $2,880.
2. Dental: $30 x 12 = $360.
3. Health FSA: $1,200, which is under the $3,400 limit in IRS Publication 15-B (2026).
4. Sec 125 total: $2,880 + $360 + $1,200 = $4,440.
5. Box 1, 3 and 5 wages: $52,000 minus $4,440 = $47,560.
6. Payroll tax saved: $4,440 x 7.65% = $339.66.
7. Federal income tax saved at the 12% bracket: $4,440 x 12% = $532.80.
8. Total tax saved: $339.66 + $532.80 = $872.46 a year.

The same $4,440 of benefits costs this worker about $3,567.54 after the tax savings. State income tax savings would add to that in most states.

What benefits can be inside a sec 125 total?

A Sec 125 total can hold any qualified benefit your employer offers through the plan. The most common are medical, dental and vision premiums and a health FSA, per IRS Publication 15-B (2026).

Premiums are not capped by the IRS the way an FSA is. They are whatever your plan costs you. KFF's 2025 Employer Health Benefits Survey found workers paid an average of $1,440 a year for single coverage and $6,850 for family coverage. If your Sec 125 total looks far above or below your enrolled benefits, ask HR which items are inside it.

If you earn above $184,500, the Social Security saving stops on the wages above that amount in 2026, so your payroll tax saving on those dollars is the 1.45% Medicare rate (Social Security Administration, 2026). Your income tax saving still applies.

Can I opt out of a sec 125 deduction?

You generally cannot opt out of a Sec 125 deduction mid-year just because you changed your mind. 26 CFR 1.125-4 says a cafeteria plan is not required to permit mid-year changes, and plans that do allow them limit them to events such as marriage, divorce, a birth or a change in employment status.

The rule exists because the tax break depends on your choice being made before the plan year starts. You can usually change your election at your employer's next open enrollment. A newer source of surprise deductions is a Section 125 wellness or indemnity plan the employer added. Benecor's guide to the Section 125 cafeteria plan wellness deduction→ explains how those work.

How do I check that my sec 125 amount is right?

You check a Sec 125 amount by matching it to the benefits you elected and confirming Box 1 wages equal gross pay minus that total. If both match, the deduction is working as designed.

1. Find your enrollment confirmation from open enrollment. It lists your cost for each benefit.
2. Add the monthly costs and multiply by 12, or by the months you were enrolled.
3. Compare that total to the year-to-date Sec 125 line on your last pay stub.
4. Check Box 1. Gross pay minus the Sec 125 total, and any other pre-tax items such as a 401(k), should equal Box 1 wages.
5. Look for an extra 125 line with no matching benefit on your confirmation. That is the one to ask HR about.

What should I ask HR about sec 125 on my W-2?

You should ask HR which benefits make up the Sec 125 total, when you elected them and whether any were added by the employer. A written answer gives you a record.

For the same topic from the other side, see this plain-English guide to what Section 125 on a W-2 means↗. Benecor's guide to less sec 125 and other cafe 125 labels→ covers pay stub wording. If you still cannot match a deduction, request a case review→ with a Benecor benefits expert.

Sources: IRS Publication 15-B, Employer's Tax Guide to Fringe Benefits (2026); IRS General Instructions for Forms W-2 and W-3 (2026); Social Security Administration, Contribution and Benefit Base and payroll tax rates (2026); 26 CFR 1.125-4, Permitted election changes (2026); Internal Revenue Code Section 125 (2026); KFF, 2025 Employer Health Benefits Survey (2025).