The core difference: when you pay taxes

A traditional IRA lets you deduct contributions from your income in the year you make them, lowering your taxable income now. You pay income tax later, when you withdraw the money in retirement. A Roth IRA takes the opposite path: you contribute money that has already been taxed, and then withdrawals in retirement are tax-free.

This single difference cascades into everything else about how these accounts work. The choice between them depends on whether you expect to be in a higher or lower tax bracket when you retire than you are now.

Key Takeaways

  • Traditional IRA contributions reduce your taxable income this year; Roth contributions do not, but Roth withdrawals in retirement are tax-free.
  • Traditional IRAs require you to start taking withdrawals at age 73; Roth IRAs have no withdrawal requirement during your lifetime.
  • You can withdraw Roth contributions (not earnings) at any time without penalty; traditional IRA early withdrawals before 59½ usually trigger a 10 percent penalty plus income tax.
  • Income limits restrict who can contribute to a Roth IRA; traditional IRAs have no income limit, though high earners may not get a tax deduction.
  • Both accounts grow tax-free year to year, but the tax treatment of that growth differs when you withdraw it.

How taxes work on contributions and withdrawals

With a traditional IRA, you write off your contribution on your tax return for that year. If you contribute $7,000 in 2024, your taxable income drops by $7,000 (assuming you meet the income and coverage requirements). When you withdraw that $7,000 plus any growth in retirement, you pay ordinary income tax on the entire amount.

With a Roth IRA, you get no tax deduction when you contribute. You pay income tax on that $7,000 in the year you earn it. But when you withdraw it in retirement—along with all the growth it has accumulated—you owe no federal income tax on any of it. This makes Roths especially valuable if your investments grow significantly over decades.

The practical choice hinges on tax brackets. If you are in a 24 percent tax bracket now and expect to be in a 12 percent bracket in retirement, a traditional IRA saves you more tax upfront. If you are in a 24 percent bracket now and expect to be in a 32 percent bracket later, a Roth locks in the lower rate.

Withdrawal rules and penalties

Traditional and Roth IRAs penalize early withdrawals differently. With a traditional IRA, any withdrawal before age 59½ is subject to a 10 percent penalty plus ordinary income tax on the amount withdrawn. A few exceptions exist—disability, medical expenses above 7.5 percent of adjusted gross income, and a handful of others—but they are narrow.

Roth IRAs are more flexible. You can withdraw your contributions (the money you put in) at any time, tax-free and penalty-free. You cannot withdraw the earnings (the growth) before 59½ without penalty, unless an exception applies. This distinction makes Roths useful as an emergency backup, since your own money is always accessible.

At age 73, traditional IRA owners must begin taking required minimum distributions (RMDs)—a set percentage of the account each year, whether they need the money or not. Roth IRAs have no RMD requirement during the account owner's lifetime, which means you can let the money grow untouched and pass it to heirs tax-free.

Income limits and contribution caps

Both account types have annual contribution limits set by the IRS. For 2024, the limit is $7,000 per person (or $8,000 if you are 50 or older). The difference is who can use them.

Roth IRAs have income phase-out ranges. If your modified adjusted gross income exceeds a certain threshold, you cannot contribute the full amount—and above a higher threshold, you cannot contribute at all. These thresholds vary by filing status and change each year. For 2024, single filers begin phasing out at $146,000 and are completely blocked at $161,000.

Traditional IRAs have no income limit on contributions themselves. However, if you or your spouse are covered by a workplace retirement plan (like a 401(k)), your ability to deduct a traditional IRA contribution phases out at higher incomes. High earners can still contribute to a traditional IRA; they just cannot deduct it from their taxes.

Tax-free growth and compounding

Both accounts grow tax-free each year. If you own stocks, bonds, or mutual funds inside either account, you do not pay capital gains tax or dividend tax as the investments grow. This tax-sheltered compounding is the main reason IRAs are powerful wealth-building tools.

The difference emerges at withdrawal. In a traditional IRA, all growth is taxed as ordinary income when you withdraw it. In a Roth, none of it is. Over 30 or 40 years, that difference can be substantial. A $10,000 investment that grows to $100,000 costs you nothing in taxes when withdrawn from a Roth, but costs you ordinary income tax on the full $100,000 if withdrawn from a traditional IRA.

Spousal and inherited account rules

If you are married and your spouse has little or no income, you can fund a spousal IRA in their name using your income. This works for both traditional and Roth accounts and effectively doubles your annual contribution room. The spouse does not have to work; you just have to have earned income equal to the total you are contributing.

When an IRA owner dies, the rules for heirs changed significantly in 2023 under the SECURE Act. Non-spouse heirs must now withdraw the entire inherited account within 10 years (with some exceptions for disabled or chronically ill beneficiaries). The tax treatment depends on the account type: inherited traditional IRA withdrawals are taxable; inherited Roth withdrawals are tax-free.

Which account makes sense for your situation

Choose a traditional IRA if you want to lower your taxable income this year, expect to be in a lower tax bracket in retirement, or earn too much to contribute to a Roth. It is also useful if you have self-employment income and want to pair it with a SEP-IRA or Solo 401(k) for larger contributions.

Choose a Roth IRA if you are early in your career (likely in a lower bracket now), expect significant income growth, want tax-free withdrawals in retirement, or value the flexibility of accessing your contributions without penalty. Roths are also valuable if you want to leave tax-assistance programs to heirs or do not want to be forced to withdraw at 73.

Many people benefit from having both. You can contribute to a traditional IRA and a Roth in the same year, as long as your combined contributions do not exceed the annual limit. This approach—sometimes called a "split strategy"—lets you hedge against uncertainty about future tax rates.

Frequently Asked Questions

Can I convert a traditional IRA to a Roth?

Yes. A Roth conversion means moving money from a traditional IRA to a Roth IRA. You pay income tax on the amount converted in that year, but the money then grows tax-free in the Roth. There is no income limit on conversions, making them useful for high earners who cannot contribute directly to a Roth. Conversions are permanent; you cannot undo them.

What happens if I withdraw from a Roth before 59½?

You can withdraw your contributions anytime, tax-free and penalty-free. Withdrawing earnings before 59½ triggers a 10 percent penalty plus income tax, unless you meet a narrow exception (disability, first-time home purchase up to $10,000 lifetime, or a few others). The five-year rule also applies: you must have owned the Roth for at least five years before withdrawing earnings tax-free.

Do I have to take money out of my traditional IRA at retirement?

Not immediately, but starting at age 73, you must take required minimum distributions each year based on your age and account balance. The amount is calculated using IRS life expectancy tables. Failing to take an RMD results in a 25 percent penalty on the amount you should have withdrawn (reduced to 10 percent if corrected within two years).

Which account grows faster, Roth or traditional?

Both grow at the same rate year to year because both are tax-sheltered. The difference is the tax bill when you withdraw. A Roth ends up with more spendable money in retirement because withdrawals are tax-free, but the account balance itself grows identically in both cases.

Can I contribute to both a traditional and Roth IRA in the same year?

Yes, but your combined contributions across all IRAs cannot exceed the annual limit ($7,000 in 2024, or $8,000 if 50 or older). If you contribute $4,000 to a traditional IRA, you can contribute only $3,000 to a Roth that year. Income limits on Roth contributions still apply.