401k vs Roth IRA
A 401k is a workplace retirement plan with a menu chosen by the employer, often with a matching contribution. A Roth IRA is opened by the individual with a far wider investment choice and a different tax treatment, so the two are frequently used together.
Two tax-advantaged retirement accounts that get compared as though you had to pick one. Most people who have access to both use both, and the interesting question is the order.
What each one is
A 401k is a workplace retirement plan. Your employer chooses the provider and the menu of funds, and many plans add a matching contribution. The 401k covers it.
A Roth IRA is an account you open yourself. You choose the provider and can hold almost anything available on that platform. Roth IRA covers it.
Both shelter growth from tax while the money stays inside. The rules for getting money in and out differ, and they differ by person and over time, which is why this page stays structural.
Where they differ
Whether somebody adds money. A match is a return available nowhere else, and it is the single largest difference between the two accounts for anybody whose plan offers one.
Who chooses the investments. The workplace menu is fixed by the employer; the self-opened account can hold almost anything the provider offers.
What the fees look like. A plan menu may carry costs you cannot avoid without leaving the plan. A self-opened account lets you choose the cheapest available option directly.
How the money is taxed. In a traditional 401k you contribute before income tax, so you get the tax break now and pay tax when you withdraw. In a Roth IRA you contribute money you have already paid tax on, and qualified withdrawals (after age 59½ and at least five years after your first Roth contribution) come out tax-free. Many workplace plans also offer a Roth 401k option, which works the Roth way inside the workplace plan.
Who is allowed to contribute. Anyone offered the plan can put money into a 401k. A Roth IRA needs earned income, and direct contributions phase out as income rises: for 2026 the IRS range is $153,000 to $168,000 for single filers and $242,000 to $252,000 for married couples filing jointly.
How much can go in. For 2026 the IRS limit is $24,500 of your own 401k deferrals (plus an $8,000 catch-up from age 50, or $11,250 at ages 60 to 63), against $7,500 for all your IRAs combined ($8,600 from age 50). From 2026, a 401k saver whose wages from that employer topped $150,000 the year before must make any catch-up as Roth contributions, so for them the two accounts meet in the same tax treatment. Limits change most years, so check the current year’s figures before you contribute.
Where they agree
Both shelter growth while the money stays inside. That is the shared advantage, and it compounds over decades rather than showing up in any single year.
Both are eaten by costs at the same rate. A basis point is one hundredth of a percent, so 75 basis points is a fee of 0.75% a year. On this site’s arithmetic a 5-basis-point annual drag removes 1.5% of a thirty-year pot, 20 basis points removes 5.8%, 75 removes 20.2% and 150 removes 36.5%.
Both hold whatever you put in them. Neither account is an investment; the choice of what sits inside matters far more than the wrapper.
And both spend most of their time below a prior high. In the S&P 500 since 1950, 93% of trading days closed below the previous record, and the longest wait for a new record was 7.5 years, from 1973 to 1980.
Which one to use: 401k or Roth IRA?
Contribute to the workplace plan at least as far as the match. It is the one part of this comparison that is not a trade-off, because the money simply does not exist otherwise.
Use the Roth after that when you want the wider choice and your income is under the limit. Being able to hold a very low-cost broad fund directly is worth real money over thirty years.
Use the Roth when the workplace menu is expensive. A plan whose cheapest option carries a high ongoing charge is a reason to put additional money elsewhere.
And use both when you can. They are not alternatives, and the order — match first, then the wider menu — is the practical answer for most people with access to each.
Why the fee inside matters more than the wrapper
Because it compounds against you every year. Moving from 75 basis points to 20 keeps 14.4 percentage points more of a thirty-year pot on this site’s arithmetic, which is larger than most people’s account-choice decision.
And because it is the variable you control. Returns are not yours to set; the ongoing charge on what you hold is.
What to check in either account
Whether a match exists and what it requires. The contribution rate needed to receive it in full is the first number to find.
The cheapest fund on the menu. Not the default, the cheapest broad one — and what it actually costs per year.
Any account-level charges. Some plans and some providers add a fee on top of the fund’s own, and that stacks with everything above.
And what you actually hold. In the S&P 500 since 1950, 93% of trading days closed below the previous record, so the allocation you can sit through matters more than the one that looks best on paper.
The original data
The 401k appears in 22 titles at a median of 81,626 across 20 channels, and the Roth IRA in 24 at a median of 95,293 across 15. Repeat appearances of the same video count once.
22 and 24 videos, at medians of 81,626 and 95,293. Tiny counts and enormous audiences — retirement accounts are among the least covered and most watched subjects measured anywhere in this corpus.
The question: Limited money. Which account first?
The answer is the match, if there is one. A matched contribution is money that appears only because you contributed — and no fund selection in either account produces a comparable step up.
When it fails
The failure is leaving a match on the table while optimizing everything else, and it costs more than any fund choice.
Hours go into comparing accounts, fund expense ratios and tax treatment, while the workplace contribution sits below the level that receives the full match. The optimization is real and small; the match is simple and large. On this site’s arithmetic even the difference between a 5-basis-point and a 75-basis-point fund — 18.7% of a thirty-year pot — is a slower effect than money not contributed at all.
The second failure is holding the default fund without checking its cost. Defaults vary.
A third is treating either account as an investment. They are containers: after you deposit, choose a fund, or the money just sits in cash.
A fourth is choosing an allocation you cannot sit through. Since 1950 the S&P 500 has closed below its prior record on 93% of trading days.
A fifth is ignoring account-level charges. They stack on top of fund fees.
And a sixth is assuming the rules are the same for everybody. They are not, and they change.
Related
The 401k covers the workplace plan. Roth IRA covers the self-opened account. And traditional IRA covers the other common individual wrapper.
The match is the part that is not close. Everything else on this page is a reasonable trade-off; a match is money that exists only if you contribute, and no allocation decision anywhere in either account competes with it. The rules differ by person and change over time.
— Michael Whitman
This page is educational, not financial advice. Test every idea on your own charts before risking money.