The Direct Answer
An IRA is a tax wrapper for your retirement investments. The investments inside a Roth and a traditional IRA can be identical, index funds, stocks, bonds. The only difference is when the IRS takes its cut.
Traditional IRA: pay later. Your contributions may be tax-deductible, so you skip income tax on that money this year. The money grows tax-deferred, and you pay ordinary income tax on withdrawals in retirement. The tax break is front-loaded.
Roth IRA: pay now. Your contributions come from after-tax dollars, no deduction this year. The money grows and is withdrawn completely tax-free in retirement, as long as the account is at least 5 years old and you are 59 and a half or older. The tax break is back-loaded.
Everything else in this guide is a consequence of that one distinction.
Worked Example: Where the Taxes Land
Say you are in the 25% tax bracket today and you have $7,500 to put toward retirement. Here is what happens in each account, assuming 7% annual growth for 30 years.
Traditional. You contribute the full $7,500 pre-tax. If the contribution is deductible, you save $1,875 on this year's taxes (25% of $7,500), so the contribution really cost you $5,625 out of pocket. The $7,500 grows for 30 years: $7,500 x 1.07^30 = $57,092. In retirement you withdraw it and pay income tax, so if you are still at 25%, you keep $42,819 after tax.
Roth. You pay the $1,875 in tax first, so $5,625 goes in. It grows the same way: $5,625 x 1.07^30 = $42,819. You withdraw it tax-free and keep all $42,819.
Notice the final numbers are identical. This is the key mathematical fact people miss: when your tax rate is the same at contribution and at withdrawal, Roth and traditional produce exactly the same after-tax result. The math is symmetric because multiplying before and after the tax is the same operation. So the entire decision is a bet on which tax rate will be higher: yours today, or yours in retirement. Run the growth yourself in our compound interest calculator to see how much the compounding amplifies whichever side you pick.
2026 Contribution Limits and Income Rules
These are the IRS figures for 2026, per IRS Publication 590-A. Verify them at irs.gov before filing, because the IRS adjusts them yearly.
| Rule | 2026 figure |
|---|---|
| IRA contribution limit, under age 50 | $7,500 |
| IRA contribution limit, age 50 and older | $8,600 |
| Catch-up contribution, age 50 and older | $1,100 |
| Roth eligibility phase-out, single / head of household (MAGI) | $153,000 - $168,000 |
| Roth eligibility phase-out, married filing jointly (MAGI) | $242,000 - $252,000 |
| Roth eligibility phase-out, married filing separately | $0 - $10,000 |
| Traditional deduction phase-out, single, covered by a workplace plan (MAGI) | $81,000 - $91,000 |
| Traditional deduction phase-out, married filing jointly, contributing spouse covered (MAGI) | $129,000 - $149,000 |
| Contribution deadline for tax year 2026 | April 15, 2027 |
Three things to notice. First, the limit is combined: $7,500 is the total across all IRAs you own, so you cannot put $7,500 in each. Second, the Roth phase-out is about eligibility, whether you can contribute at all, while the traditional phase-out is about deductibility, whether you get the tax break. You can always contribute to a traditional IRA regardless of income; the question is whether it is deductible. Third, you need earned income at least equal to your contribution. No earned income means no IRA contribution that year.
The Core Decision Rule
Forget the dozens of articles comparing pros and cons. The decision is one comparison:
If your marginal tax rate is higher today than it will be in retirement, pick traditional. Take the deduction now at the high rate, pay tax later at the low rate.
If your marginal tax rate is lower today than it will be in retirement, pick Roth. Pay tax now at the low rate, withdraw tax-free later when your rate would have been high.
The catch is that nobody knows future tax rates for certain. So work with what you know. If you are in the 12% or 22% bracket, Roth is usually the right call, because 22% is likely the lowest rate you will see for decades. If you are in the 32% or 35% bracket at your peak earnings, traditional usually wins, because your retirement income will probably land you in a lower bracket. If the rates look close, the Roth's secondary perks break the tie: no required minimum distributions, tax-free withdrawals give you flexibility to manage your bracket in retirement, and your contributions double as an emergency backstop since you can withdraw them anytime without tax or penalty.
Where Each Account Wins
The young lower earner. You are 25, earning $45,000, in the 12% bracket. Your earnings will almost certainly grow faster than inflation for the next 30 years. Roth wins. You pay 12% now and get decades of tax-free growth. This is the single strongest Roth case there is.
The peak earner. You are 48, earning $220,000, in the 35% bracket, saving hard. Your retirement income will not be taxed at 35%. Traditional wins. The deduction at 35% is worth far more than tax-free withdrawals would be later. Note the income trap here: at $220,000 you are still eligible for a Roth contribution (the single phase-out starts at $153,000), but if you are covered by a workplace retirement plan, the traditional deduction phases out at $81,000 to $91,000, so a deductible traditional IRA is off the table anyway.
The employer match note. If you have a 401(k), contribute there first up to the employer match, because a match is a 50 to 100% instant return and no IRA can beat it. But know this: the 401(k) match your employer puts in is always pre-tax, traditional money, regardless of whether your own contributions are Roth or traditional. So even Roth-heavy savers end up with a traditional balance by default.
The hedger. If you genuinely cannot predict your future bracket, split the contribution. Put half in Roth and half in traditional. The combined limit applies to both together, and tax diversification means you have options in retirement: pull from the traditional account in low-income years and the Roth in high-income years to keep your effective rate down.
Roth Conversions and the Backdoor
Two mechanisms worth knowing exist for people the income limits shut out. A Roth conversion moves money from a traditional IRA into a Roth. There is no income limit on conversions, but you pay income tax on the converted amount in the year you convert, so the math is the same now-versus-later bet. The backdoor Roth is a two-step move for high earners above the Roth income limits: contribute to a traditional IRA without taking a deduction, then convert it to a Roth. If you have no other pre-tax IRA money, the conversion is essentially tax-free. If you do have other pre-tax IRA money, the pro-rata rule taxes part of the conversion, which is the classic gotcha to check before trying it.
Who Should Choose Which
Choose Roth if: you are early in your career in a low bracket; you expect your income to rise substantially; you want maximum flexibility, since contributions are always withdrawable and there are no required distributions; or you expect taxes to rise in the future.
Choose traditional if: you are in your peak earning years in a high bracket; you are covered by a workplace plan and still within the deduction phase-out ($81,000 to $91,000 single for 2026); you expect a much lower income in retirement; or you need the deduction now to keep your tax bill manageable.
Either way, the far more important decision is contributing at all. An imperfect account choice still beats the cash you never invested, and decades of compounding dwarf the tax difference. If you have high-interest debt competing for the same dollars, our debt snowball vs avalanche guide will help you decide what to kill first. Once the money is invested, it feeds the same growth engine described in what is coast FIRE: early dollars doing decades of work.
How to Open One
Opening an IRA takes about 15 minutes. Pick any major brokerage, open a Roth or traditional IRA account online, fund it from your bank, and choose an investment, a total-market index fund is the default sensible choice. There is no endorsement here; any large brokerage offers the same account types. Set up automatic monthly contributions so you stop relying on willpower. The 2026 deadline is April 15, 2027, so contributions made in early 2027 can still count for 2026 if you designate them as such, but do not wait. Every month a contribution sits uninvested is a month of compounding lost.
Frequently Asked Questions
Can I have both a Roth IRA and a traditional IRA?
Yes. The 2026 contribution limit of $7,500 ($8,600 if you are 50 or older) applies to all your IRAs combined, not per account. You can split it any way you want, for example $4,000 into a Roth and $3,500 into a traditional IRA in the same year, as long as the total stays at or under the limit.
What happens if I contribute too much to an IRA?
An excess contribution is penalized 6% of the excess amount for every year it stays in the account. You can fix it by withdrawing the excess (plus any earnings on it) before your tax filing deadline, including extensions, which generally avoids the penalty. If you leave the excess in place, you can also absorb it by contributing less in the next year, but the 6% penalty applies for each year the excess remains.
Is a Roth IRA always better for young people?
Not automatically, though it usually is. Young earners typically sit in lower tax brackets now and higher ones later, which is exactly the case where Roth wins. The exception is a young person in a high tax bracket, such as a high-paid graduate in a high-tax state, where a deductible traditional contribution may save more in taxes today than the Roth would later. The decision rule is your tax rate now versus your expected rate in retirement, not your age alone.
Do I need earned income to contribute to an IRA?
Yes. You must have taxable compensation, meaning wages, salaries, or self-employment income, at least equal to your contribution. You cannot contribute more than you earned. One exception: a working spouse can contribute to a spousal IRA for a non-working spouse, as long as the couple files jointly and the working spouse earned enough to cover both contributions.
What is the deadline for 2026 IRA contributions?
April 15, 2027. You can contribute for tax year 2026 any time during 2026 and up to the April tax filing deadline of the following year, without an extension. Contributions made between January 1 and April 15, 2027 must be designated as 2026 contributions with your brokerage.
Are Roth IRA withdrawals really tax-free?
Qualified withdrawals are completely tax-free, but two conditions must hold: your Roth IRA must have been open for at least 5 years, and you must be at least 59 and a half (or meet an exception such as disability or a first-home purchase up to $10,000). Your original contributions are different: you can withdraw what you put in at any time, at any age, with no tax and no penalty, because you already paid tax on that money. Non-qualified withdrawals of earnings are taxed as income plus a 10% penalty.
Keep Reading: Finance Guides
Whichever account you pick, the growth comes from compounding, so run your contribution through our free compound interest calculator to see the decades-long difference. To understand the engine behind those numbers, read what is coast FIRE, the point where your savings start funding retirement on their own. And if debt is competing with retirement for your dollars, debt snowball vs avalanche settles which balance to attack first.