What Are Pretax Contributions and How Do They Work?

Pretax contributions are portions of your paycheck that go into a retirement, health, or dependent care account before federal and state income taxes are calculated on your earnings. By lowering the income the IRS sees, they reduce what you owe now and let the money grow untaxed until you take it out. The tradeoff is straightforward: a smaller tax bill today, ordinary income tax on the money when you eventually withdraw it.

How the Paycheck Math Works

When you elect a pretax contribution, your employer’s payroll system subtracts that amount from your gross pay before calculating income-tax withholding. If you earn $70,000 a year and put $10,000 into a pretax 401(k), your taxable wages drop to $60,000 for income-tax purposes. You still earned $70,000, but the IRS only taxes you on what’s left after the contribution.1Consumer Financial Protection Bureau. Understanding Paycheck Deductions

The savings show up in every paycheck rather than as a refund at tax time. The money moves directly from your employer into the account and never lands in your bank account as spendable cash.

What Pretax Does Not Shield You From

“Pretax” does not mean tax-free. Contributions to a 401(k), 403(b), or 457(b) are exempt from federal income tax withholding, but they are still subject to Social Security and Medicare (FICA) taxes. Your employer reports the full amount of your elective deferrals in the Social Security and Medicare wage boxes on your W-2.2Internal Revenue Service. Retirement Plan FAQs Regarding Contributions

Contributions made through a Section 125 cafeteria plan get broader relief. That category covers Health Savings Accounts funded through payroll, health Flexible Spending Accounts, and Dependent Care FSAs. Because these benefits are excluded from gross income under Section 125, they escape Social Security, Medicare, and federal income taxes.3Social Security Administration. Cafeteria Benefit Plans That’s an extra 7.65 percent in FICA savings on every dollar routed through a cafeteria-plan account compared with a retirement deferral of the same size.

Accounts That Accept Pretax Contributions

Several account types allow pretax contributions, each aimed at a different category of worker.

  • 401(k) plans, for private-sector employees, authorized under 26 U.S.C. § 401(k). State and local governments and tax-exempt organizations generally cannot offer them.4Office of the Law Revision Counsel. 26 USC 401
  • 403(b) plans, for employees of public schools, colleges, hospitals, churches, and certain nonprofits.5U.S. Securities and Exchange Commission. 403(b) and 457(b) Plans
  • 457(b) plans, for state and local government workers and some nonprofit employees.
  • SIMPLE IRA plans, offered by small businesses under the Savings Incentive Match Plan for Employees.
  • Traditional IRAs, open to anyone with earned income. The tax benefit is claimed as a deduction on your return rather than through payroll.6Office of the Law Revision Counsel. 26 USC 408
  • Health Savings Accounts, available if you’re enrolled in a high-deductible health plan.7Office of the Law Revision Counsel. 26 USC 223
  • Health and Dependent Care Flexible Spending Accounts, offered through an employer’s Section 125 cafeteria plan.8Office of the Law Revision Counsel. 26 USC 125

Traditional IRA contributions are pretax in effect, but the deduction may be reduced or eliminated if you or your spouse is covered by a workplace plan and your income exceeds annual thresholds. If neither of you participates in a workplace plan, the full contribution is deductible regardless of income.9Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500

2026 Contribution Limits

The IRS adjusts these caps each year for inflation. For 2026:

HSAs stand apart from the other health accounts in two ways. The balance is portable and stays with you when you change jobs or retire, and qualified medical withdrawals are tax-free at any age. FSA balances, by contrast, are generally forfeited at the end of the plan year unless your employer offers the grace period or carryover.

Pretax or Roth

Many workplace plans now offer a Roth option alongside the pretax one. The annual dollar limits are the same, but the tax treatment is reversed. Pretax contributions skip tax now and are taxed on the way out. Roth contributions are made with after-tax dollars, and qualified withdrawals of both the contributions and their earnings come out tax-free.15Internal Revenue Service. Roth Comparison Chart

Neither is universally better. Pretax tends to favor workers who expect to be in a lower tax bracket in retirement, since the withdrawal will be taxed at that lower rate. Roth tends to favor those who expect their rate to hold steady or rise. Splitting contributions between the two is a common way to hedge that guess.

How the Money Is Taxed When You Take It Out

Because pretax dollars were never taxed on the way in, every dollar you withdraw from a pretax retirement account is ordinary income, including both your original contributions and the investment earnings. The rate depends on your tax bracket in the year you take the distribution.

Withdrawals before age 59½ generally trigger an additional 10 percent tax on top of the regular income tax.16Office of the Law Revision Counsel. 26 USC 72 Several exceptions can waive that penalty, including disability, a series of substantially equal periodic payments, separation from service at 55 or later for workplace plans, unreimbursed medical expenses, up to $5,000 per child for birth or adoption expenses, and, for IRAs only, up to $10,000 over your lifetime toward a first home.17Internal Revenue Service. Retirement Topics – Exceptions to Tax on Early Distributions Regular income tax on the withdrawal still applies even when a penalty exception does.

You also cannot leave the money in forever. Federal law requires Required Minimum Distributions starting in the year you turn 73, calculated from your account balance and an IRS life-expectancy factor. Missing an RMD carries an excise tax of 25 percent of the shortfall, dropping to 10 percent if you correct it within two years.18Internal Revenue Service. Retirement Plan and IRA Required Minimum Distributions FAQs

If You Contribute Too Much

Excess 401(k) deferrals should be flagged to your plan administrator, who then returns the excess and any earnings on it before April 15 of the following year. That April 15 deadline is fixed and is not pushed back by a tax-return extension.10Internal Revenue Service. Retirement Topics – 401(k) and Profit-Sharing Plan Contribution Limits Corrected on time, the returned excess is taxed in the year of the deferral and the earnings in the year distributed, with no 10 percent early-withdrawal penalty. Miss the deadline and the excess is taxed both when contributed and again when eventually distributed.19Internal Revenue Service. Consequences to a Participant Who Makes Excess Annual Salary Deferrals

Excess IRA contributions carry a 6 percent excise tax for each year the excess stays in the account.20Office of the Law Revision Counsel. 26 USC 4973 To avoid the tax, withdraw the excess and its earnings by the due date of your return, including extensions; if you’ve already filed, you have six months from the original due date to fix it and file an amended return.21Internal Revenue Service. Instructions for Form 5329 The same 6 percent excise tax applies to uncorrected excess HSA contributions.