401k vs Traditional IRA
A 401k is a workplace retirement plan with a menu chosen by the employer and often an employer match. A traditional IRA is opened by the individual with a far wider fund choice, so the match and the cost of the available funds are what separate them in practice.
Two retirement wrappers with similar sheltering. What actually differs day to day is whether an employer adds money and what the funds available inside each one cost.
What each one is
A 401k is a workplace retirement plan. The employer picks the provider and the menu, and many plans add a matching contribution. The 401k covers it.
A traditional IRA is opened by the individual. You choose the provider and can hold almost anything that platform offers. Traditional IRA covers it.
Both shelter growth while the money stays inside. The detailed rules differ by person and change over time, so this page stays on the structural differences.
Where they differ
Whether somebody adds money. A match is available in one and not the other. Where a plan offers one, it dwarfs everything else on this page.
Who chooses the funds. A fixed menu against an open one. That decides what the cheapest available option costs, which is the second-largest factor here.
What the account itself charges. Some plans add an administrative fee on top of the fund’s own, and that stacks with everything else you pay.
How much can go in. Contribution limits differ between the two and change over time, so the current figures are something to look up rather than remember.
Where they agree
Both shelter growth while the money stays inside. That is the shared advantage and it compounds quietly rather than showing up in any single year.
Both are eaten by costs identically. The ladder measured here runs from 5 basis points costing 1.5% of a thirty-year pot to 20 costing 5.8%, 75 costing 20.2% and 150 costing 36.5%.
Both are containers, not investments. What you hold inside decides almost all of the outcome, and the wrapper decides very little of it.
And both sit through drawdowns. Since 1950 the S&P 500 has ended 93% of its trading days below the previous record, with a 7.5-year wait for a new one from 1973 to 1980.
Which one to use: 401k or Traditional IRA?
Contribute to the workplace plan at least to the match. It is the only part of this comparison that is not a trade-off, since the money exists only if you contribute.
Use the individual account after that when the menu is better. Being able to hold a very low-cost broad fund directly is worth real money across thirty years.
Use the individual account when the plan charges an administrative fee you cannot avoid. Those stack on top of the fund cost and are easy to miss entirely.
And use both when you can. They are not alternatives, and the sensible order is match first, then whichever menu is cheaper.
Why the fund cost outweighs the wrapper
Because it compounds against you annually. Moving from 75 basis points to 20 keeps 14.4% more of a thirty-year pot on this site’s arithmetic — a larger effect than most account-choice decisions.
And because it is the variable you control. The return is not yours to set; the ongoing charge on what you hold is.
What to check in either
Whether a match exists and what it requires. The contribution rate that receives it in full is the first number to find.
The cheapest broad fund available in each. Not the default — the cheapest, and its annual cost.
Any account-level charge. Some plans and some providers add one, and it stacks with the fund fee.
And what you actually hold. In the S&P 500 since 1950, 93% of trading days closed below the previous record, so an allocation you can sit through matters more than the one that looks best on a spreadsheet.
What the contribution limits change
They cap how much shelter you can use each year. The figures differ between the two accounts and they change over time, so the current numbers are something to look up rather than carry in your head.
A match does not always count toward the same cap. How employer money is treated is a plan-specific question and it changes what your own contribution has to be.
A lower cap does not make an account worse. It makes it a smaller part of the plan, which usually argues for using both rather than choosing.
And filling either cap is rarer than the debate suggests. For most people the binding constraint is how much can be contributed at all, not which wrapper it goes into.
The original data
The 401k appears in 22 titles at a median of 81,626 across 20 channels, and the traditional IRA in just 2 at a median of 75,293. Each video is counted once, even when several searches returned it.
22 videos on one and 2 on the other, at medians of 81,626 and 75,293. Almost nothing made and very large audiences on both — two videos is far too small a sample to conclude anything about the second figure beyond that the subject is barely covered.
The question: Match already taken. Where does the next dollar go?
The answer is whichever menu is cheaper. Past the match, the wrapper difference is small and the fund cost is not — so compare the two cheapest broad options and let that decide.
When it fails
The failure is leaving a match unclaimed while comparing wrappers, and it costs more than the comparison could ever win. Time goes into researching account types while the workplace contribution sits below the level that receives the full match. The research is real and small; the match is simple and large. Even the gap between a 5-basis-point and a 75-basis-point fund — 18.7% of a thirty-year pot on this site’s arithmetic — accumulates more slowly than money never contributed.
The second failure is holding the default fund unexamined. Defaults vary widely.
A third is ignoring plan administrative fees. They stack on fund costs.
A fourth is treating either account as an investment. Both are containers.
A fifth is assuming contribution limits are the same. They differ and change.
And a sixth is picking an allocation you cannot sit through. The S&P 500 has spent 93% of its trading days since 1950 below an earlier record close.
Related
The 401k covers the workplace plan. Traditional IRA covers the individual account. And Roth IRA covers the other common individual wrapper.
These two shelter growth in broadly similar ways, so the interesting comparison is not the tax treatment — it is the match and the menu. One of those is free money and the other is a fee you pay every year for thirty years.
— Michael Whitman
This page is educational, not financial advice. Test every idea on your own charts before risking money.