What Are Pre-Tax Deductions on My Paycheck? Types and Tax Savings

Pre-tax deductions on your paycheck are amounts your employer subtracts from your gross pay before calculating your federal income tax and, in some cases, your Social Security and Medicare taxes. The result is a smaller taxable wage figure and a smaller tax bill in that pay period. The usual suspects are traditional 401(k) or 403(b) contributions, health insurance premiums, health savings account and flexible spending account contributions, and qualified commuter benefits.

How Pre-Tax Deductions Lower Your Taxes

The mechanic is simple. Say you earn $5,000 in a pay period and contribute $500 to a traditional 401(k). Your employer runs income tax withholding on $4,500, not $5,000. You still owe tax on that $500 eventually, when you pull it out of the retirement account, but you skip the tax today.

Post-tax deductions run in the other direction. Taxes come out of the full $5,000 first, then the deduction is subtracted from what’s left. Roth 401(k) contributions, wage garnishments, and most union dues work this way, so a dollar contributed post-tax reduces your take-home pay by more than a dollar contributed pre-tax.

There’s a secondary benefit. Pre-tax deductions reduce your adjusted gross income, which is the figure the IRS uses to determine whether you qualify for various credits and deductions that phase out as income rises. A lower AGI can keep you under those thresholds.

What You’ll Typically See on a Paycheck

Retirement Plan Contributions

Contributions to a traditional 401(k), 403(b), or governmental 457(b) are the most recognizable pre-tax line on a pay stub. The contribution is excluded from your current taxable income and grows tax-deferred until you take withdrawals, when it’s taxed as ordinary income. For 2026, the employee elective deferral limit is $24,500.¹

If your employer matches, those matching dollars don’t count against your limit and aren’t included in your current taxable income either.

Health Insurance Premiums

The premiums you pay toward employer-sponsored health, dental, and vision coverage are usually the largest pre-tax item on a paycheck. They flow through a Section 125 cafeteria plan, the legal structure that lets your employer deduct them before calculating both income tax and payroll taxes.² Because these deductions cut both taxes, they save you more per dollar than a retirement contribution does.

Health Savings Account Contributions

A health savings account is available only if you’re enrolled in a qualifying high-deductible health plan. HSAs get three tax advantages at once: contributions are pre-tax, the balance grows tax-free, and withdrawals for qualified medical expenses are tax-free. The account belongs to you, not your employer, so it moves with you when you change jobs. For 2026, the contribution limit is $4,400 for self-only coverage and $8,750 for family coverage.³

Flexible Spending Accounts

A health care FSA lets you set aside pre-tax money for out-of-pocket medical costs like copays, prescriptions, and eyeglasses. The 2026 maximum employee contribution is $3,400.⁴ Unlike an HSA, an FSA is generally use-it-or-lose-it. Unspent funds at the end of the plan year are forfeited, though some plans allow a grace period or a small carryover.

A dependent care FSA covers qualifying childcare or elder care expenses while you work. The annual limit is $7,500 per household, or $3,750 if you’re married filing separately.⁵ Both FSA types run through a Section 125 plan, so contributions reduce your income tax and FICA tax.

Commuter Benefits

Qualified transportation fringe benefits cover mass transit passes, vanpool costs, and qualified parking. Your employer can let you pay for these expenses with pre-tax dollars under Section 132(f).⁶ For 2026, the monthly exclusion is $340 for transit and vanpool combined, plus a separate $340 for qualified parking.⁷

Group-Term Life Insurance

Your employer can provide up to $50,000 of group-term life insurance coverage tax-free, and the cost of that coverage doesn’t show up in your taxable wages at all. If coverage exceeds $50,000, though, the cost of the excess is added back to your wages as “imputed income,” which appears on your pay stub and W-2 even though you never received the money as cash. It’s calculated using an IRS age-based table and is subject to Social Security and Medicare taxes.⁸ So if you see a line marked GTL or imputed income that seems to increase your taxable wages, that’s what it is.

Income Tax Savings vs. FICA Savings

Not all pre-tax deductions reduce your taxes the same way, and this is where people get tripped up. FICA taxes fund Social Security (6.2% of wages up to the $184,500 wage base in 2026) and Medicare (1.45% of all wages, plus an additional 0.9% on wages above $200,000).⁹

Health insurance premiums, FSA contributions, and HSA contributions processed through a Section 125 cafeteria plan reduce your wages for both income tax and FICA purposes. Every dollar you contribute saves income tax plus 7.65% in FICA.²

Traditional 401(k) and 403(b) contributions work differently. They reduce your income for federal and state income tax, but the full contribution is still subject to Social Security and Medicare taxes. That’s why your W-2 will show a lower number in Box 1 (income tax wages) than in Boxes 3 and 5 (Social Security and Medicare wages).¹⁰

2026 Contribution Limits

The IRS adjusts most of these ceilings annually for inflation. The key ones for 2026:

Changing Your Elections During the Year

Retirement contributions are flexible. Most employers let you raise, lower, or stop your 401(k) or 403(b) contributions at any time, subject to how quickly payroll can process the change. You can adjust throughout the year as long as you don’t exceed the annual limit.

Health-related benefits are far more rigid. Elections for health insurance premiums, FSAs, and other Section 125 benefits are locked in for the plan year once you make them. Annual open enrollment, typically late in the calendar year, is your main window to adjust for the following year.

Outside open enrollment, you can only change these elections after a qualifying life event: getting married or divorced, having or adopting a child, losing other health coverage, or a change in your or your spouse’s employment that affects benefit eligibility.¹² You typically have 30 to 60 days after the event to notify your plan administrator. Miss the window and you’re stuck with your current elections until open enrollment comes around again.

Verifying Everything on Your W-2

Your year-end Form W-2 is where all of this lands. Box 1 shows your wages after pre-tax deductions have been subtracted for income tax purposes. Boxes 3 and 5 show Social Security and Medicare wages, which will be higher than Box 1 if you made traditional 401(k) contributions, since those reduce income tax wages but not FICA wages.¹⁰

Box 12 breaks out specific pre-tax contributions using letter codes:¹³

Code D: traditional 401(k) elective deferrals
Code E: 403(b) salary reduction contributions
Code G: 457(b) elective deferrals
Code W: HSA contributions, including any your employer made
Code AA: designated Roth 401(k) contributions (these are post-tax but tracked here)

Compare the Box 12 amounts against your final pay stub for the year. If the numbers don’t line up, call your employer’s payroll department before you file. Fixing a discrepancy in January is straightforward. Fixing one after the IRS flags a mismatch months later is not.

1
Internal Revenue Service. Retirement Topics – 401(k) and Profit-Sharing Plan Contribution Limits
2
Internal Revenue Service. FAQs for Government Entities Regarding Cafeteria Plans
3
HealthCare.gov. Understanding Health Savings Account-eligible Plans
4
Internal Revenue Service. Publication 15-B – Employer’s Tax Guide to Fringe Benefits
5
Office of the Law Revision Counsel. 26 USC 129 – Dependent Care Assistance Programs
6
Office of the Law Revision Counsel. 26 US Code 132 – Certain Fringe Benefits
7
Internal Revenue Service. Publication 15-B (2026), Employer’s Tax Guide to Fringe Benefits
8
Internal Revenue Service. Group-Term Life Insurance
9
Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates
10
Internal Revenue Service. Retirement Plan FAQs Regarding Contributions – Are Retirement Plan Contributions Subject to Withholding for FICA, Medicare or Federal Income Tax
11
Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500
12
HealthCare.gov. Qualifying Life Event
13
Internal Revenue Service. General Instructions for Forms W-2 and W-3