The core difference: who runs it and when you pay taxes

A Roth IRA is an account you open and manage yourself, usually through a bank or brokerage. A 401(k) is a workplace retirement plan your employer sets up and administers. The tax timing is opposite: you contribute to a Roth with money you've already paid income tax on, and withdrawals in retirement are tax-free. With a 401(k), contributions reduce your taxable income now, but you pay income tax on withdrawals later.

This difference matters because it changes how much you actually have to spend in retirement. If you expect to be in a higher tax bracket when you retire, a Roth saves you money. If you expect to be in a lower bracket, a 401(k) saves you money now.

Key Takeaways

  • A Roth IRA is self-directed and funded with after-tax dollars; a 401(k) is employer-sponsored and funded with pre-tax dollars that reduce your current taxable income.
  • Roth IRA withdrawals in retirement are tax-free; 401(k) withdrawals are taxed as ordinary income.
  • A 401(k) often includes employer matching contributions, which is assistance programs; a Roth IRA does not.
  • Roth IRAs have no required withdrawals in your lifetime; 401(k)s require you to start withdrawing at age 73.
  • You can withdraw Roth IRA contributions (not earnings) at any time without penalty; 401(k) early withdrawals before age 59½ usually trigger a 10 percent penalty plus taxes.

Contribution limits and employer matching

For 2024, you can contribute up to $7,000 per year to a Roth IRA if you are under 50, or $8,000 if you are 50 or older. These limits reset each January. A 401(k) has a much higher limit: $23,500 per year under 50, or $31,000 at 50 and older.

The real advantage of a 401(k) is employer matching. If your employer offers it, they contribute money to your account based on what you contribute—often 50 cents for every dollar you put in, up to 6 percent of your salary. That is immediate return on your money. A Roth IRA has no matching because it is your account alone.

If your employer offers a 401(k) match, financial advisors typically recommend contributing enough to capture the full match before maxing out a Roth IRA. The match is money you do not have to earn yourself.

How withdrawals work before and after retirement

With a Roth IRA, you can withdraw the money you contributed (called your basis) at any time, for any reason, without penalty or taxes. You cannot withdraw the earnings on that money without penalty until you are 59½ and have held the account for at least five years. This flexibility makes a Roth useful as an emergency fund if you have no other savings.

A 401(k) is locked until age 59½. If you withdraw before that age, you owe income tax on the full amount plus a 10 percent penalty. Some plans allow loans against your balance, which you repay with interest, but that is a loan, not a withdrawal. A few plans have a "hardship withdrawal" option for specific situations like medical bills or eviction, but these still trigger taxes and penalties.

Once you reach age 59½, both accounts let you withdraw freely. However, a 401(k) requires you to start taking withdrawals at age 73, whether you need the money or not. A Roth IRA has no required withdrawals during your lifetime, which means you can leave the money untouched to grow and pass it to heirs.

Income limits and who can open each account

Anyone with earned income can open a Roth IRA, but there are income limits on how much you can contribute. For 2024, if you are single and earn more than $146,000, your contribution limit begins to phase out. If you earn more than $161,000, you cannot contribute to a Roth at all. These limits are higher for married couples filing jointly and change each year.

A 401(k) has no income limits. If your employer offers one, you can participate regardless of how much you earn. This makes a 401(k) the only option for high earners who want to save large amounts for retirement.

You must have a workplace 401(k) available to you to use one. Self-employed people and small business owners can open a Solo 401(k) or a SEP IRA instead, which work similarly but are designed for people without employees.

Investment choices and control

With a Roth IRA, you choose where to open the account and what to invest in. You can buy individual stocks, bonds, mutual funds, exchange-traded funds, or hold cash. You have complete control and can change your investments whenever you want.

A 401(k) limits you to the investment options your employer's plan offers. Most plans offer 10 to 30 mutual funds or target-date funds, but you cannot buy individual stocks or bonds directly. You are also locked into the plan's rules about when and how you can change investments.

This matters if you have strong preferences about how your money is invested or if you want to use specific strategies. A Roth gives you that freedom; a 401(k) does not.

Taxes on inherited accounts

If you leave a Roth IRA to heirs, they can withdraw the money tax-free, though they must empty the account within 10 years under current law. If you leave a 401(k) to heirs, they owe income tax on all withdrawals. This is a significant advantage of a Roth for people who want to leave money to family.

The rules for inherited retirement accounts changed in 2023 and continue to evolve, so heirs should check with a tax professional about their specific situation. But the basic principle holds: Roth withdrawals are tax-free for heirs, and 401(k) withdrawals are taxed.

Which one should you prioritize

If your employer offers a 401(k) with matching, contribute enough to get the full match first. That is assistance programs and should be your first priority. After that, if you are under the Roth income limits, open a Roth IRA and contribute what you can. Then go back to the 401(k) if you have more money to save.

If you do not have access to a 401(k) or you are self-employed, a Roth IRA is usually the best option for most people because of the tax-free withdrawals and flexibility. If you are a high earner above the Roth income limits, a 401(k) is your main tool for large retirement savings.

Frequently Asked Questions

Can I have both a Roth IRA and a 401(k) at the same time?

Yes. Many people have both. You can contribute to a 401(k) through your employer and also open and fund a Roth IRA on your own. The contribution limits are separate, so you are not choosing between them—you can use both to save more for retirement.

What happens to my 401(k) if I leave my job?

You stop contributing, but the money stays in the account unless you move it. You can leave it where it is, roll it into your new employer's 401(k) if they allow it, or roll it into a Roth or traditional IRA. A rollover does not trigger taxes if you do it correctly, but moving money from a traditional 401(k) to a Roth IRA does create a taxable event.

Can I convert a 401(k) to a Roth IRA?

Yes, through a process called a Roth conversion. You move money from a traditional 401(k) or IRA into a Roth IRA. You owe income tax on the amount converted in that year, but future withdrawals are tax-free. This strategy makes sense if you expect tax rates to rise or if you are in a low-income year.

Do I pay taxes twice on a Roth IRA contribution?

No. You pay income tax on the money before you contribute it to the Roth. Once it is in the account, it grows tax-free and you never pay taxes on it again. You pay tax once, upfront, not twice.

What if my employer does not offer a 401(k)?

Open a Roth IRA if you are under the income limits, or a traditional IRA if you are not. If you are self-employed, you can open a Solo 401(k) or SEP IRA, which allow much higher contributions than a regular IRA. A financial advisor or tax professional can help you choose which one fits your situation.