401k Tax Rules: Contributions vs withdrawals

Saving for retirement can seem intimidating at any stage in your career. Maybe you’re just starting out at your first job, or you’ve been working for a while and realize you’ll need more than you’ve previously saved to retire. Enrolling in your employer’s 401(k) plan is a great way to make sure you’re putting money aside for your later years. But before you get started, it’s important to understand how 401(k) tax rules might affect you.

How do 401(k) plans work?

A 401(k) plan lets you contribute a portion of your wages to an investment account that’s titled in your name. The money comes out of your paycheck automatically, making it a convenient way to plan for retirement. Some employers also make matching contributions up to a certain amount (for example, up to 5% of your salary).¹

If your employer contributes to your 401(k), make sure you understand your company’s vesting policy. Some organizations may require you to work for a set amount of time before you fully own the funds your employer adds to your account. If you leave the company before the funds become fully vested, your employer may take back the funds they’ve contributed.²

There are two types of 401(k) plans: traditional and Roth.³ They’re subject to different tax rules. Understanding the implications of each can help you make smarter choices about your future.

Note that you may not always have a choice between a traditional and Roth 401(k) plan. Your options for 401(k) plans are limited to what your employer offers. If you’re interested in other ways to save for retirement, you might consider retirement accounts like IRAs, which aren’t tied to your employer and have their own tax rules.

How are 401(k) contributions taxed?

Every dollar you put into your 401(k) will affect your tax situation at some point.⁴ And since you’re allowed to contribute up to $24,500 per year in 2026 (or more, if you’re over 50),⁵ that impact can be significant.

Let's look at the different tax implications for each type of 401(k) plan.

Traditional 401(k) contributions

Traditional 401(k) accounts are tax-deferred, meaning you don’t pay taxes on the money in your account until you withdraw the funds. Your contributions to a traditional 401(k) come out of your pre-tax income — the amount you earn before taxes are taken out. You don’t pay taxes on the money you or your employer adds to your traditional 401(k) or on the investment gains in the account until you start making withdrawals.

Roth 401(k) contributions

Roth 401(k) accounts are funded with after-tax dollars, which means the money you contribute comes out of your paycheck after taxes have been deducted. Contributions are not tax deductible. When the time comes, withdrawals and qualified distributions are tax-free.

Employer matches for a Roth 401(k) can be a little more complicated. Often, employer contributions are made on a pre-tax basis, go into a separate traditional 401(k) account and aren’t taxed until withdrawal. However, in some cases, the employer can contribute to your Roth 401(k) directly.⁶ Taxes are taken out of these direct employer contributions when they’re deposited into your account.⁷

How are 401(k) withdrawals taxed?

Just as some 401(k) contributions are taxed differently, so are withdrawals.

Traditional 401(k) withdrawals

Because traditional 401(k) contributions aren’t taxed when they are deposited into your retirement account, they’re taxed as income when you withdraw the funds. However, you only pay taxes on what you withdraw, so unless you cash out the entire retirement account at once, you won’t feel the full weight of those taxes in any given year.⁸

You may withdraw money from a traditional 401(k) without penalty once you turn 59½, or if you meet some exceptions, like:⁹

• If you become disabled or terminally ill,
• If you experience a financial loss as the result of a federally declared disaster, or
• If you lose your job when you’re over age 55.

However, traditional 401(k)s require you to begin taking out a certain amount of money — called a required minimum distribution, or RMD — every year once you reach a certain age — 73 in 2026 — or stop working, whichever comes later. The amount of your RMD is based on your age and projected life expectancy.

In some cases, your plan may automatically withhold a portion of your traditional 401(k) distributions to cover the income tax.¹⁰ Depending on how much other income you have, you may still owe some taxes at the end of the year.

Roth 401(k) withdrawals

Because your Roth 401(k) is funded with after-tax money, you don’t pay any tax on qualified withdrawals. To make a qualified withdrawal, you must be at least 59½ years old and have had the account for over five years, whichever is later.

There’s no RMD or age at which you must start taking distributions from your Roth 401(k).¹¹ However, if you pass away and named a beneficiary for your account, the beneficiary must take RMDs.¹²

401(k) early withdrawal penalty

Whether you have a traditional or Roth 401(k), the tax rules are designed so that you have to wait until you’re 59½ before you can withdraw your money without paying a penalty. In the case of Roth 401(k) plans, you also need to have had the account open for at least five years. You’re allowed to take the money out before that, but you’ll owe a 10% early withdrawal penalty on the amount you withdraw plus income taxes on early withdrawals from a traditional 401(k).

The IRS recognizes several exceptions for traditional 401(k) early withdrawals, mainly related to financial hardship.¹³ For Roth 401(k) plans, there are only two: total disability or death (in which case the money passes to your beneficiaries without penalty).¹⁴

It may be tempting to withdraw from a 401(k) before retirement if you find yourself in a pinch, but it has long-term consequences. Even if the money is helpful now, it could put you in a tough financial position when you retire, and you’ll need to pay penalties on what you take out. You might consider whether a personal loan or a 401(k) loan could help you access the funds you need without compromising your retirement fund.

How to maximize your 401(k)

To make the most of your 401(k) plan, consider your financial situation today and what you think it may be when you get older. Social Security, pensions, inheritances, your spouse’s income and any other money you have will affect your taxes as well.

Decide when you want to pay taxes

If your employer offers you the choice of a traditional or a Roth 401(k), you may be wondering how each option would affect the timing of your taxes. If you want to lower your taxes now, you might favor a traditional 401(k), since you won’t pay taxes on that money until you withdraw it. But, if you want to minimize the income tax you pay in retirement, a Roth 401(k) might make more sense. Some people also opt to split the difference and put money in both types of 401(k)s, if available.

Consider your tax bracket

Your 401(k) may affect your taxes in another way by changing your tax bracket. A tax bracket is a range of incomes assigned to a certain tax rate. Lower earners pay a lower tax rate— in some cases 0% — while higher earners pay more.¹⁵

A traditional 401(k) may be better if you think you’ll be in a lower tax bracket when you retire than while you’re working, because your tax rate may likely be lower then. A Roth 401(k) tends to be more helpful for people who might find themselves in a higher bracket — and facing a higher tax rate — during retirement.¹⁶

It’s important to note that income tax brackets are marginal, meaning that once you move into a higher tax bracket, the higher tax rate only applies to the amount above the limit of your previous tax bracket.¹⁷

Consider converting your traditional 401(k) into a Roth 401(k) plan

If you realize you’re going to have more income in retirement than you originally planned for, converting a traditional 401(k) into a Roth 401(k) may be one strategy for saving on taxes after you retire — but you’ll have to be ready for a big tax bill the year that you do make the change.¹⁸

Remember that you haven’t paid income tax on traditional 401(k) contributions yet. You’ll have to do that before turning that account into a Roth 401(k) (which uses after-tax dollars). So, before you begin, figure out how much tax you’ll owe and make sure you have enough money on hand to cover it.

Not all companies offer the option of converting your traditional 401(k) to a Roth 401(k). If you’re not sure of your employer’s rules, check with your human resources or payroll department.

Plan withdrawals carefully

If you have a traditional 401(k), you can start taking penalty-free distributions at age 59½, but you don’t have to until it’s time to start drawing your RMDs. Since you pay income tax on everything you withdraw, you can help keep your tax bill in check by withdrawing only as much as you need.

If you have a Roth 401(k), you have more flexibility. Your withdrawals are tax-free, and you can take them any time as long as you’re older than 59½ and have had the account for more than five years.

Keep in mind that minimizing taxes is only one part of the puzzle, however. You also want to keep your investments growing, so you don’t run out of money. For example, it may make more sense to spend your taxable money first so your tax-free money can continue to grow.¹⁹ A financial advisor can help you come up with a spending plan that aligns with your long-term financial goals.

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Make tax-smart moves for your retirement savings

Understanding how your 401(k) is taxed is a necessary part of smart retirement planning, and it can help you make the right decisions for both your present and your future. It’s important to remember that what’s best for you depends on your individual situation. Be sure to consult with a tax professional like a CPA so you can fully understand the tax implications of any decision you make about your 401(k).

Sources

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11, 12. https://www.irs.gov/retirement-plans/retirement-plan-and-ira-required-minimum-distributions-faqs
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14. https://www.irs.gov/retirement-plans/plan-participant-employee/retirement-topics-designated-roth-account
15, 17. https://www.nerdwallet.com/article/taxes/federal-income-tax-brackets
16. https://www.investopedia.com/articles/investing/102216/understanding-401ks-and-all-their-benefits.asp
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19. https://www.bankrate.com/retirement/retirement-withdrawal-strategies/#impacts