What Is a Non-Roth 401(k)? Contributions, Taxes, and Withdrawals

A non-Roth 401(k) is a traditional, pre-tax 401(k): the standard employer-sponsored retirement account where your contributions come out of your paycheck before federal income tax is calculated, and every dollar you eventually withdraw is taxed as ordinary income. It’s the original flavor of the 401(k), distinguished from the Roth 401(k), which flips the tax treatment by taxing contributions now and letting qualified withdrawals come out tax-free. For 2026, you can defer up to $24,500 of salary into one, with more room if you’re 50 or older.

How the Pre-Tax Mechanism Works

When you enroll, your employer’s payroll system routes a portion of your gross pay into the account before calculating federal (and usually state) income tax withholding. Earn $70,000, contribute $10,000, and the IRS treats your taxable wages as $60,000 for income-tax purposes. That immediate tax reduction is the whole appeal. More money stays invested and compounds over the decades between now and retirement.

One thing catches people off guard. Pre-tax 401(k) contributions still get hit with Social Security and Medicare (FICA) taxes. Your employer withholds those payroll taxes on the full $70,000, not the reduced $60,000. The deferral applies only to income tax.1Internal Revenue Service. Are Retirement Plan Contributions Subject to Withholding for FICA, Medicare, or Federal Income Tax

The bet with a traditional 401(k) is that your tax rate in retirement will be lower than it is now. If you’re in your peak earning years and expect to draw a smaller income later, that bet often pays off. If you expect your income or tax rates to rise, a Roth 401(k) may fit better. Many plans let you split contributions between both types.

2026 Contribution Limits

The IRS adjusts 401(k) caps annually for inflation. The 2026 numbers:

Only compensation up to $360,000 counts for 401(k) calculations in 2026, so if you earn more than that, your employer’s matching formula ignores everything above the cap.3Internal Revenue Service. 2026 Amounts Relating to Retirement Plans and IRAs, as Adjusted

Employer Matching and Vesting

Most employers match part of what you put in. A common formula is 50 cents per dollar you contribute, up to 6% of your salary, though structures vary. Employer matching dollars always go in pre-tax, even when your own contributions are Roth, and those matched funds grow tax-deferred until you withdraw them.

Your own contributions are always 100% yours, immediately.4Internal Revenue Service. Retirement Topics – Vesting Employer contributions are a different story. Your plan’s vesting schedule determines how much of the match you actually own, based on your years of service. Federal law allows two structures. Cliff vesting means you own 0% of employer contributions until you complete three years of service, then jump to 100%. Graded vesting phases ownership in over six years, starting at 20% after two years and increasing annually until you’re fully vested at year six.5U.S. Department of Labor. FAQs about Retirement Plans and ERISA

Safe harbor 401(k) plans and SIMPLE 401(k) plans require immediate vesting of all employer contributions.5U.S. Department of Labor. FAQs about Retirement Plans and ERISA If you’re thinking about leaving a job, check your vesting percentage first. Walking away one year short of full vesting can mean forfeiting thousands.

How Withdrawals Are Taxed

This is where the government collects on the tax break it gave you years ago. Every dollar you pull from a traditional 401(k), original contributions and investment growth alike, is taxed as ordinary income. A $50,000 withdrawal stacks on top of Social Security, any pension, and other income to determine your bracket. Federal income tax rates for 2025 range from 10% to 37%.6Internal Revenue Service. Federal Income Tax Rates and Brackets

If you take a distribution paid directly to you instead of rolling it into another retirement account, the plan administrator must withhold 20% for federal tax up front.7Internal Revenue Service. 401(k) Resource Guide Plan Participants General Distribution Rules That withholding is essentially a deposit against your tax bill for the year; you reconcile the actual amount when you file.

The Early Withdrawal Penalty and Its Exceptions

Taking money out before age 59½ generally triggers a 10% additional tax on top of regular income tax.7Internal Revenue Service. 401(k) Resource Guide Plan Participants General Distribution Rules On a $20,000 early withdrawal in the 22% bracket, that’s roughly $6,400 in combined taxes and penalties.

Several exceptions eliminate the 10% penalty, though you still owe ordinary income tax on the withdrawal:8Internal Revenue Service. Retirement Topics – Exceptions to Tax on Early Distributions

  • Separation from service at 55 or older. If you leave your employer during or after the year you turn 55, you can withdraw from that employer’s 401(k) penalty-free. This is often called the Rule of 55. For qualified public safety employees, the age drops to 50.
  • Total and permanent disability.
  • A Qualified Domestic Relations Order. Distributions to a former spouse under a court-approved divorce order are penalty-free for the recipient.
  • Unreimbursed medical expenses exceeding 7.5% of your adjusted gross income.
  • Substantially equal periodic payments. You can set up a series of roughly equal annual withdrawals based on your life expectancy. Once started, they must continue for at least five years or until you reach 59½, whichever comes later. Modifying the payments early triggers a retroactive recapture tax.9Internal Revenue Service. Substantially Equal Periodic Payments
  • Birth or adoption: up to $5,000 per child for qualified expenses.
  • Federally declared disaster: up to $22,000 if you suffered an economic loss from a qualifying disaster.
  • Domestic abuse victim: up to the lesser of $10,000 or 50% of your vested account balance.

The Rule of 55 surprises most people planning early retirement. It applies only to the 401(k) at the employer you’re leaving, not to old 401(k)s from previous jobs or to IRAs. If you rolled older accounts into your current plan before separating, those consolidated funds would qualify.

When Withdrawals Become Required

The tax deferral doesn’t last forever. Under current rules, required minimum distributions must begin by April 1 of the year after you turn 73.10Internal Revenue Service. Retirement Plan and IRA Required Minimum Distributions FAQs The SECURE 2.0 Act moves this age to 75 starting in 2033, so if you were born in 1960 or later, you get extra years of tax-deferred growth.

Your annual RMD is calculated by dividing your account balance as of December 31 of the prior year by a life expectancy factor from IRS tables. The older you get, the larger the percentage you must withdraw.

One exception that applies specifically to 401(k) plans: if you’re still working for the employer that sponsors the plan, you can delay RMDs from that plan until you actually retire, provided your plan allows the delay.11Internal Revenue Service. Retirement Topics – Required Minimum Distributions (RMDs) This does not apply to IRAs or plans from former employers.

Missing an RMD is expensive. The excise tax on any shortfall is 25% of the amount you failed to withdraw. If you correct the mistake within the correction window, generally by the end of the second year after the shortfall, the penalty drops to 10%.12Office of the Law Revision Counsel. 26 U.S.C. 4974 – Excise Tax on Certain Accumulations in Qualified Retirement Plans You report the penalty on IRS Form 5329.13Internal Revenue Service. About Form 5329, Additional Taxes on Qualified Plans (Including IRAs) and Other Tax-Favored Accounts

What Happens to the Account When You Leave Your Job

When you separate from an employer, you generally have four options for the money in that company’s 401(k):

  • Leave it in the old plan. If your balance exceeds the plan’s minimum threshold, often $5,000, you can usually leave the account where it is. You can’t make new contributions, but the investments keep growing tax-deferred.
  • Roll it into your new employer’s plan. If your next employer accepts incoming rollovers, a direct transfer keeps the money tax-deferred and consolidates your accounts.
  • Roll it into a traditional IRA. This gives you a broader range of investment options, and a direct rollover avoids tax withholding.14Internal Revenue Service. Rollovers of Retirement Plan and IRA Distributions
  • Cash it out. You’ll owe income tax on the entire balance, the plan will withhold 20% immediately, and the 10% penalty applies if you’re under 59½. This is almost always the worst choice.

With a direct rollover, the money moves from one custodian to another without passing through your hands, and nothing is withheld. With an indirect rollover, the plan cuts you a check, withholds 20%, and you have 60 days to deposit the full distribution (including the withheld portion, which you have to replace from other funds) into a new retirement account. Miss the 60-day window and the entire distribution becomes taxable income, potentially plus the 10% penalty.14Internal Revenue Service. Rollovers of Retirement Plan and IRA Distributions Direct is simpler and safer.