How Are 401(k) Withdrawals Taxed?

If you have a traditional 401(k), every withdrawal is taxed as regular income, just like wages. You add the withdrawal to your other income for the year, and you pay whatever tax rate applies. If you have a Roth 401(k), qualified withdrawals are normally tax free.

That is the whole story in two sentences. The details below explain the difference between the two kinds of accounts, the extra 10% penalty for taking money too early, and why the amount withheld from your payment is not the same as what you might owe in April.

For the bigger picture, our guide to how taxes work in retirement covers all retirement income sources together, including Social Security.

Traditional vs Roth: the key difference

A traditional 401(k) lets you save money before income tax. If you earn $60,000 and put $6,000 in, you only pay income tax on $54,000 that year. The trade is simple: skip the tax now, pay it later, when you take the money out.

A Roth 401(k) works the other way around. You pay income tax on the money first, put the taxed amount in the account, and never pay tax on it again. Qualified withdrawals are tax free.

To be "qualified," a Roth withdrawal must happen when you are at least 59½ years old AND the account must have been open for at least five years. This five-year clock starts January 1 of the first year you put money into the Roth part of this 401(k), which the IRS calls a designated Roth account. A Roth IRA held somewhere else is a separate account with its own clock, so it does not fill this requirement by itself. Moving Roth 401(k) money to another account by rollover carries the clock over under special IRS rules, so look up the IRS guidance before you roll anything.

One wrinkle worth knowing: with a Roth 401(k), match money can land in the pre-tax pot even when your own contributions are Roth. Employer matches do not automatically become Roth. Only your plan documents say how the match is treated, so read them or ask the plan administrator.

Taking money before age 59½

Withdraw early from a traditional 401(k) and two things happen:

1. The withdrawal counts as income and gets taxed at your normal rates.
2. Most people also owe an extra 10% early withdrawal penalty on top.

The penalty has exceptions. Some common ones:

• Age 55 separation rule: if you leave your job in the year you turn 55 or later, withdrawals from THAT employer's 401(k) escape the penalty. This does not apply to IRAs.
• Substantially equal payments (sometimes called 72(t) payments): you agree to take out the same-size amount every year for at least five years, with the size based on your life expectancy. Those payments escape the 10% penalty, though you still pay normal income tax on them.
• Disability, and several other special cases.

For example, say you withdraw $10,000 from a traditional 401(k) at age 48 with no exception. The 10% penalty costs $1,000. You would also pay normal income tax on the $10,000, whatever your tax bracket makes that.

Before touching money early, it is worth checking whether an exception applies. Our post on retiring early when benefits start later walks through the timing problem early retirees face with Social Security and Medicare.

Why the amount withheld is not your final bill

When you request a withdrawal, the plan holds back some money for the IRS automatically. This is called withholding, money sent to the tax office ahead of filing. It is a down payment on your tax bill, not the bill itself.

For example, say you ask for $20,000 and the plan withholds 20%, which is $4,000. You receive $16,000. But suppose your actual tax on that withdrawal turns out to be $2,800. Come tax season, you get the extra $1,200 back. Reverse the numbers and you could owe more in April than was held back.

Two points flow from this:

• Your true cost is your tax bracket, not the withholding percentage.
• Withdrawing a large amount in one year can push part of it into a higher bracket. Spreading withdrawals over several years sometimes lowers the total tax, depending on your situation.

Required minimum distributions

The government does not let traditional 401(k) money sit untouched forever, because it went in untaxed. Once you reach a starting age that depends on the year you were born, you must take a minimum amount out each year. These are called required minimum distributions, or RMDs. The exact age that applies to you is spelled out on the IRS page linked below. Each withdrawal counts as regular income, same as always.

Skip an RMD or take too little, and there is a penalty for the shortfall. Roth 401(k)s follow different RMD rules, and the details have changed recently, so confirm your numbers with the IRS rules for required minimum distributions.

If you expect big RMDs later, planning the years just before 73 can matter. Our post about delaying CPP and OAS covers the Canadian side of that timing puzzle, and the Social Security timing guide covers the US version.

A worked example, step by step

Here is how the tax gets figured on a traditional 401(k) withdrawal. All the rates and deductions below are made-up round numbers chosen so the math is easy to follow. Real amounts change every year, so look them up on IRS.gov before you act.

Suppose you are 66, single, retired, and withdraw $40,000 from a traditional 401(k). You have no other income besides $2,000 of bank interest.

Step	Amount
401(k) withdrawal	$40,000
Bank interest	$2,000
Total income	$42,000
Minus standard deduction (example figure)	−$15,000
Taxable income	$27,000

Now apply the example tax rates: 10% on the first $12,000 of taxable income, 12% above that.

• First $12,000 × 10% = $1,200
• Next $15,000 ($27,000 minus $12,000) × 12% = $1,800
• Total tax = $3,000

So the $40,000 withdrawal cost $3,000 in tax, about 7.5 cents per dollar. That is far less than any headline "top tax rate," because much of the withdrawal sits in lower brackets. Notice something else: if you had withdrawn $80,000 instead, only the upper slice would climb into higher brackets, not everything.

Your own number depends on your deduction, your other income, and your state. Some states tax these withdrawals fully, some tax them lightly, and some do not tax income at all. Check your own state's tax office for its rule.

Ways the bill can come out smaller

Nothing here is advice, because the right move depends on your health, your other income, and how long you expect to need the money. But three levers exist, educationally speaking:

• Spread withdrawals across years. Filling the low brackets evenly over ten years often beats emptying the account quickly.
• Mix account types. Pulling from taxable savings in high-bracket years and from the 401(k) in leaner years can smooth the total.
• Plan around claiming ages. There can be gaps between when you stop working and when Social Security starts, and those gaps are often the cheapest years to take 401(k) money.

Nobody can see all these moving parts in their head. That is the gap When Can I Retire fills: enter your accounts, and it works out the age you can retire and how ready you are today, showing every step of the math including taxes and the years before benefits start. The check is free, and you can upload a statement or type the numbers yourself.