For most 401(k) plans, 401(k) taxes only apply on withdrawals. Most 401(k) plans are tax-deferred, which means no income tax on contributions or on gains, interest or dividends the money produces until the owner withdraws it.
That makes the 401(k) not just a way to save for retirement; it’s also a great way to cut your tax bill. But there are a few rules about 401(k) taxes to know, as well as a few strategies that can get your tax bill even lower. Here’s an overview of how 401(k) taxes work, how a 401(k) can affect your tax return and how to pay less tax when the IRS asks for a cut of your retirement savings.
401(k) taxes on contributions
Contributions to a traditional 401(k) plan come out of your paycheck before the IRS takes its cut. So if you earn $1,000 before taxes at work and you contribute $200 of it to your 401(k), that's $200 less that you'll be taxed on. When you file your tax return, you’d report $800 rather than $1,000.
In 2020 and 2021, you can contribute up to $19,500 a year to a 401(k) plan. If you’re 50 or older, you can contribute $26,000.
You still have to pay Medicare and Social Security taxes on your payroll contributions to a 401(k).
The annual contribution limit is per person, and it applies to all of your 401(k) account contributions in total.
If your employer offers a Roth 401(k), that means you contribute after-tax money instead of pre-tax money as with the traditional 401(k). This has a few advantages (see the section about withdrawals).
See more ways to save and invest for the future
401(k) taxes while your money is in the account
While money is in a traditional 401(k), you pay no taxes on investment gains, interest or dividends. This is true for a Roth 401(k), as well.
Roth 401(k) vs. traditional 401(k)
Tax treatment of contributions
Contributions are made pretax, which reduces your current adjusted gross income.
Contributions are made after taxes, with no effect on current adjusted gross income. Employer matching dollars must go into a pretax account and are taxed when distributed.
Tax treatment of withdrawals
Distributions in retirement are taxed as ordinary income.
No taxes on qualified distributions in retirement.
Withdrawals of contributions and earnings are taxed. Distributions may be penalized if taken before age 59½, unless you meet one of the IRS exceptions.
Withdrawals of contributions and earnings are not taxed as long as the distribution is considered qualified by the IRS: The account has been held for five years or more and the distribution is:
Unlike a Roth IRA, you cannot withdraw contributions any time you choose.
401(k) taxes on withdrawals
In technical terms, your contributions and the investment growth in a traditional 401(k) are tax-deferred — that is, you don't pay taxes on the money until you make withdrawals from the account. At that point, you’ll owe income taxes to Uncle Sam.
If you’re in a Roth 401(k), in most cases you won’t owe any taxes at all when you withdraw the money because you will have already paid the taxes upfront.
401(k) taxes if you withdraw the money when you retire
For traditional 401(k)s, the money you withdraw is taxable as regular income — like income from a job — in the year you take the distribution (remember, you didn’t pay income taxes on it back when you put it in the account; now it’s time to pay the piper). For Roth 401(k)s, the money you withdraw is not taxable (you already paid the income taxes on it back when you put the money in the account). You can begin withdrawing money from your traditional 401(k) without penalty when you turn age 59½.
You can begin withdrawing money from your Roth 401(k) without penalty once you’ve held the account for at least five years and you’re at least 59½.
If you’ve retired, you have to start taking required minimum distributions from your account when you're 72.
If you don’t take the required minimum distribution when you’re supposed to, the IRS can assess a penalty of 50% of the amount not distributed.
You can withdraw more than the minimum.
» MORE: See what tax bracket you’re in
401(k) taxes if you withdraw the money early
For traditional 401(k)s, there are three big consequences of an early withdrawal or cashing out before age 59½:
Taxes will be withheld. The IRS generally requires automatic withholding of 20% of a 401(k) early withdrawal for taxes. So if you withdraw the $10,000 in your 401(k) at age 40, you may get only about $8,000.
The IRS will penalize you. If you withdraw money from your 401(k) before you’re 59½, the IRS usually assesses a 10% penalty when you file your tax return. That could mean giving the government another $1,000 of that $10,000 withdrawal.
You may have less money for later, especially if the market is down when you start making withdrawals. That could have long-term consequences.
There are a lot of exceptions. This article has more details, but in a nutshell, you might be able to escape the IRS’s 10% penalty for early withdrawals from a traditional 401(k) if you:
Receive the payout over time.
Qualify for a hardship distribution with the plan administrator.
Leave your job and are over a certain age.
Are getting divorced.
Give birth to a child or adopt a child.
Are or become disabled.
Put the money in another retirement account.
Use the money to pay an IRS levy.
Use the money to pay certain medical expenses.
Were a disaster victim.
Overcontributed to your 401(k).
Were in the military.
You can withdraw money from a Roth 401(k) early if you’ve held the account for at least five years and need the money due to disability or death.
7 ways to reduce your 401(k) taxes
Wait as long as you can to take money out of your account. Withdrawals are what can trigger taxes.
If you must make an early withdrawal from a 401(k), see if you qualify for an exception that will help you avoid paying an early withdrawal penalty.
See if you qualify for the Saver’s Credit on your contributions.
Borrow from your 401(k) instead of making an early withdrawal. Not all 401(k) plans offer loans, though. Also, in most circumstances you’ll need to repay the loan within five years and make regular payments. Check with your plan administrator for the rules.
Use tax-loss harvesting. You might be able to offset the taxes on your 401(k) withdrawal by selling underperforming securities at a loss in some other regular investment account you might have. Those losses can offset some or all of the taxes on your 401(k) withdrawal.
See a tax professional. There are other ways to minimize your 401(k) taxes, too, so find a qualified tax pro and discuss your options.