A Roth IRA uses after-tax money, not pre-tax

When you contribute to a Roth IRA, you use money you have already paid income tax on. This is the opposite of a traditional IRA or a 401(k), where you contribute pre-tax dollars and reduce your taxable income for that year. With a Roth, you get no tax deduction when you put the money in, but the money grows tax-free and you pay no tax when you withdraw it in retirement.

The trade-off matters most if you are in a high tax bracket now or expect to be in a lower one later. If you think your tax rate will be higher in retirement, a Roth makes sense because you lock in today's lower rate. If you think your rate will be lower, a traditional pre-tax account may save you more money overall.

Both account types have annual contribution limits set by the IRS. For 2024, you can contribute up to $7,000 to either a Roth or traditional IRA if you are under 50, or $8,000 if you are 50 or older. You cannot contribute to both in the same year and exceed the combined limit.

Key Takeaways

  • Roth IRAs accept after-tax contributions, meaning you pay income tax on the money before it goes into the account.
  • Traditional IRAs and 401(k)s use pre-tax contributions, which lower your taxable income in the year you contribute.
  • Roth withdrawals in retirement are tax-free, while traditional account withdrawals are taxed as ordinary income.
  • Your income level may limit whether you can contribute to a Roth in a given year, depending on IRS rules.
  • You can own both a Roth and a traditional IRA, but your total contributions across both cannot exceed the annual limit.

How pre-tax and after-tax contributions work in practice

When you contribute $7,000 to a traditional IRA, you reduce your taxable income by $7,000 for that year. If you earn $60,000 and contribute $7,000 to a traditional IRA, you report only $53,000 as taxable income. That means you owe less tax to the IRS that year.

When you contribute $7,000 to a Roth IRA, your taxable income stays at $60,000. You already paid tax on that $7,000 when you earned it. The $7,000 goes into the Roth with no deduction, but once it is inside, all growth is tax-free forever.

At withdrawal time, the difference becomes clear. If you withdraw $20,000 from a traditional IRA in retirement, that entire $20,000 counts as income and is taxed at your ordinary income tax rate. If you withdraw $20,000 from a Roth IRA, you owe zero tax on it, because you already paid tax on the original contribution and all the growth happened tax-free.

Income limits for Roth contributions

Not everyone can contribute to a Roth IRA. The IRS sets income limits that change each year. For 2024, if you file as single, you can make a full contribution if your modified adjusted gross income (MAGI) is below $146,000. If your MAGI is between $146,000 and $161,000, you can make a partial contribution. Above $161,000, you cannot contribute to a Roth at all that year.

If you are married and file jointly, the limits are higher. For 2024, you can make a full contribution if your MAGI is below $230,000, a partial contribution between $230,000 and $240,000, and no contribution above $240,000.

These limits do not explore to traditional IRAs. Anyone with earned income can contribute to a traditional IRA, though the tax deduction phases out if you or your spouse has a workplace retirement plan and your income is above a certain level. The income limits for Roth are about preventing high earners from using Roth as a tax shelter, since the tax-free growth benefit is most valuable over decades.

When a Roth makes more sense than a traditional account

A Roth is often the better choice if you are young and expect to work for many decades. The longer your money sits in the account, the more growth happens tax-free. A 25-year-old who contributes $7,000 to a Roth and does not touch it until age 67 will have paid tax on only the original $7,000, not on 42 years of investment gains.

A Roth also makes sense if you expect your tax rate to be higher in retirement than it is now. If you are in the 22% tax bracket today but think you will be in the 32% bracket in retirement, paying tax now at 22% is cheaper than paying it later at 32%.

A Roth is also useful if you want flexibility in retirement. You can withdraw your contributions (not the earnings) from a Roth at any time without penalty or tax. With a traditional IRA, early withdrawals before age 59½ usually trigger a 10% penalty plus income tax. This makes a Roth a better emergency fund if you are not sure you can leave the money untouched.

When a traditional pre-tax account makes more sense

A traditional IRA or 401(k) is often better if you are in a high tax bracket now and expect to be in a lower one in retirement. If you earn $150,000 this year and expect to live on $50,000 a year in retirement, a pre-tax contribution saves you money at your current high rate and you pay tax at a lower rate later.

A traditional account also makes sense if you need the tax deduction now. If you are self-employed or have a high income and want to reduce your taxable income this year, a pre-tax contribution does that when ready. A Roth gives you no deduction, so it does not help with this year's tax bill.

A traditional account can also hold more money if you have access to a workplace 401(k) or similar plan. A 401(k) has a much higher contribution limit than an IRA — $23,500 for 2024 if you are under 50 — so if you want to save more than $7,000 a year, a pre-tax 401(k) is the only way to do it through an IRA-type account.

Required minimum distributions and other rules

Traditional IRAs require you to start taking withdrawals at age 73, whether you need the money or not. These are called required minimum distributions (RMDs), and the IRS calculates how much you must withdraw each year based on your age and account balance. If you do not take the full amount, you owe a penalty.

Roth IRAs have no RMD during your lifetime. You can leave the money in the account to grow tax-free for as long as you live, and you never have to withdraw it if you do not want to. This makes a Roth better if you do not need the money in retirement or want to leave it to heirs.

Roth accounts do have RMDs for beneficiaries after you die, but the rules are more flexible than for traditional accounts. This is another reason a Roth is often better for estate planning if you have significant assets.

Can you convert a traditional IRA to a Roth?

Yes. A Roth conversion means moving money from a traditional IRA to a Roth IRA. When you do this, you pay income tax on the amount you convert, but then that money grows tax-free in the Roth forever.

Conversions make sense if you expect your tax rate to rise, if you have a low-income year and want to convert at a lower rate, or if you want to avoid RMDs later. They do not make sense if you cannot afford to pay the tax bill out of pocket, because using money from the IRA itself to pay the tax defeats the purpose.

There are no income limits on Roth conversions, so even high earners who cannot contribute directly to a Roth can convert a traditional IRA. This is sometimes called a "backdoor Roth" and is a common strategy for high-income earners.

Frequently Asked Questions

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

Yes, but your total contributions to both accounts combined cannot exceed the annual limit. For 2024, that limit is $7,000 if you are under 50. If you contribute $4,000 to a Roth, you can contribute only $3,000 to a traditional IRA that year. The limit resets each January.

Do I pay taxes on Roth IRA earnings when I withdraw them?

No, as long as you follow the rules. You must have owned the Roth for at least five years and be at least 59½ years old when you withdraw the earnings. If you withdraw earnings before meeting both conditions, you owe income tax on the earnings plus a 10% penalty. Contributions can always be withdrawn tax-free.

What happens to my Roth IRA if I die?

Your beneficiary inherits the account and can withdraw the money. They will not owe income tax on the withdrawals, but they must follow IRS rules about how fast to empty the account. The rules changed in 2023, so check current guidance for your situation.

Is a 401(k) pre-tax or after-tax?

A traditional 401(k) is pre-tax, meaning contributions lower your taxable income. Some employers offer a Roth 401(k), which works like a Roth IRA — you contribute after-tax money and withdrawals are tax-free. The contribution limit for both types combined is $23,500 for 2024 if you are under 50.

Can I deduct a Roth IRA contribution on my taxes?

No. Roth contributions are never deductible. You use after-tax money, so there is nothing to deduct. This is the main difference from a traditional IRA, where the contribution may be fully or partially deductible depending on your income and whether you have a workplace retirement plan.