The main difference is when you pay tax. With a Roth IRA you contribute money you have already paid tax on, and qualified withdrawals in retirement are tax-free. With a traditional IRA you may get a tax deduction now, but withdrawals in retirement are taxed as ordinary income. A Roth tends to suit people who expect their tax rate to be the same or higher later. A traditional IRA tends to suit people who expect a lower rate in retirement than they pay today.
That is the short version, and it has caveats: income limits, deductibility rules, withdrawal rules, and a future tax situation nobody can know. This guide is US-only and general. Contribution limits and income thresholds change, so this article does not quote them. Check the current figures on the IRS website before acting.
What an IRA is
An individual retirement account (IRA) is a type of account, not an investment. You open it at a bank, brokerage, or other provider, and then choose investments inside it, such as index funds, bonds, or cash-like options. The account provides the tax treatment. What you invest in is a separate decision.
You generally need earned income, such as wages or self-employment income, to contribute. One combined annual limit applies across all your Roth and traditional IRAs, so you can fund both in the same year but not beyond that single cap. The IRS publishes the limit each year, including any catch-up amount for older savers.
How the traditional IRA works
You contribute money, and in many cases the contribution is tax-deductible, which lowers your taxable income this year. Earnings are not taxed while they stay in the account. When you withdraw in retirement, the withdrawals are taxed as ordinary income.
- Deductibility depends on your situation. If you or your spouse are covered by a workplace retirement plan, the deduction can shrink or disappear at higher incomes. The IRS publishes the income ranges each year.
- Early withdrawals before age 59 and a half generally face ordinary income tax plus an additional 10 percent tax, unless an exception applies. The IRS lists the exceptions, and there are quite a few.
- Required minimum distributions (RMDs) apply later in life. You must start taking money out at an age set by federal law, which has been raised in recent years and depends on your birth year. The IRS publishes the current age.
How the Roth IRA works
You contribute money that has already been taxed. There is no deduction now. The money grows, and qualified withdrawals are tax-free. In general, a withdrawal is qualified when a five-year period has passed since the first Roth contribution and you are at least 59 and a half (other conditions, such as disability, can also qualify).
- Income limits apply to direct contributions. Above a threshold your allowed contribution phases down and then out. The thresholds depend on filing status and change over time.
- Contributions can be withdrawn at any time without tax or penalty, because you already paid tax on them. Earnings follow stricter rules and can face tax and the additional 10 percent tax if taken out early.
- No required minimum distributions during the original owner’s lifetime. The IRS says these are not required until after the owner’s death.
Side-by-side comparison
| Feature | Traditional IRA | Roth IRA |
|---|---|---|
| Tax on contributions | Often deductible now | No deduction, paid with after-tax money |
| Tax on withdrawals in retirement | Ordinary income | Tax-free if qualified |
| Income limit to contribute | None to contribute, but the deduction may phase out | Direct contributions phase out at higher incomes |
| Early access to contributions | Taxes and usually a penalty apply | Contributions can be withdrawn without tax or penalty |
| Required minimum distributions | Yes | No, for the original owner |
A simple worked example
The numbers here are made up to show the logic. They are not the contribution limit, a forecast, or advice. Assume you set aside $6,000 of pre-tax pay each year for 30 years, the account grows at an illustrative 7 percent a year, and you pay a flat 22 percent tax both now and in retirement. Real returns vary and can be negative in any year.
- Traditional: The full $6,000 goes in and is deducted. After 30 years the balance is roughly $566,800. Taxed at 22 percent on withdrawal, that leaves about $442,000.
- Roth: You pay 22 percent tax first, so $4,680 goes in. After 30 years the balance is roughly $442,000, and qualified withdrawals are tax-free.
The results match because the tax rate is the same on both ends. The difference only appears when the rate changes. If your rate in retirement is lower than your rate today, traditional comes out ahead. If it is higher, the Roth does. Nobody knows their future rate, which is why many people spread contributions across both types.
The example also assumes the traditional saver invests the tax savings from the deduction. If the deduction becomes extra spending, the comparison changes.
When a Roth often makes sense
- You are early in your career with a lower income and expect higher earnings later.
- You value being able to reach your contributions in an emergency without tax or penalty (though retirement money is best left alone if you can).
- You want tax-free income in retirement to reduce uncertainty about future tax rates.
- You already hold a lot of pre-tax retirement savings and want some tax diversification.
When a traditional IRA often makes sense
- You are in a higher tax bracket now and expect a lower one in retirement.
- The deduction is available to you and meaningfully lowers this year’s tax bill.
- You are near retirement and expect lower income afterward.
If you are unsure
Many people cannot predict their future tax rates. Common approaches:
- Split contributions between both types, within the combined limit.
- Lean Roth when income is low and traditional when income peaks. This is a pattern some people follow, not a rule.
- Check your workplace plan. Many employer plans offer both pre-tax and Roth versions, and an employer match is separate from IRA decisions. Where an IRA ranks among your other goals is covered in prioritizing money goals.
What to invest in inside the account
The IRA is only the container. One common beginner choice is a low-cost broad index fund, explained in what an index fund is. Money left uninvested in an IRA earns only what the cash option pays, so check that you chose investments after depositing. Some people open an account, fund it, and never pick anything.
Downsides of each
Roth: no deduction now, so take-home pay is lower; income limits can block direct contributions; if your tax rate drops in retirement you may have paid more tax than needed.
Traditional: withdrawals are taxed at rates you cannot know today; RMDs can force taxable income later; the deduction may be unavailable at your income and coverage situation.
Both: the money is meant for retirement, and early use can be costly. An IRA is not a substitute for cash savings. Build a cushion first, using how much to keep in an emergency fund to size it. If you carry high-interest debt, the savings versus debt guide covers the trade-off.
Getting started
- Confirm you have earned income this year.
- Look up the current contribution limit and income ranges on the IRS website.
- Decide Roth, traditional, or a split.
- Open the account with a provider whose fees and account minimums fit your plan.
- Set up automatic contributions, even small ones.
- Choose an investment and check its expense ratio.
Contribution deadlines for a tax year usually run to the tax filing date the following spring, but confirm the date for the year you are working on. A tax professional can help with income limits and deductibility if your situation is not straightforward.
Where this comes from
This article is based on the IRS’s pages on Roth IRAs and traditional IRAs, the IRS guidance on the additional tax on early distributions, the IRS FAQ on required minimum distributions, and general comparisons of the two account types. The worked example is simple arithmetic with made-up inputs. Contribution limits, income thresholds, RMD ages and tax rules change, so check them at the IRS before acting. This is general information, not tax or investment advice.