Topic: Investment · Type: Evergreen · Reading time: ~8 min

Most Americans open a retirement account the way they pick a username: quickly, under mild pressure, without thinking too hard about it. According to a 2025 Gallup survey, about six in ten Americans have money in some kind of retirement account — but the research from the Investment Company Institute shows that fewer than one in five households actually makes an active annual contribution to an IRA. The rest are coasting on an old rollover from a job they left years ago.

The accounts themselves — 401(k), traditional IRA, Roth IRA — are not complicated. What's confusing is that nobody ever explains how they relate to each other, which ones you can use simultaneously, and most importantly: which one you should actually be using given your current income and where you expect to be in twenty years. This post does exactly that.

The one thing every retirement account has in common

Before the differences, one thing that applies to all of them: these accounts exist because the government wants you to save for retirement badly enough to offer you a tax deal in exchange.

The deal takes one of two forms. Either you get a tax break now — by contributing money before it's taxed, reducing your income this year — and pay taxes when you withdraw in retirement. Or you contribute after-tax money now, paying the tax upfront, and withdraw everything tax-free later. That's it. Every retirement account, everywhere, is a variation on these two structures.

Understanding which deal is better for you — pay less tax now, or pay less tax later — is the whole game. The rest is details.

Worth knowing: The Tax Cuts and Jobs Act reduced income tax rates significantly in 2017. Many of those cuts are scheduled to expire after 2025, which could push rates higher. If they do, locking in today's lower rates via a Roth account now looks increasingly attractive.

What the 401(k) actually does (and why the employer match is free money you can't ignore)

A 401(k) is an employer-sponsored account. It only exists if your employer offers it. You contribute a percentage of each paycheck before taxes, that money gets invested in whatever fund options your employer's plan provides, and you pay ordinary income tax on it when you eventually withdraw — typically after age 59½.

Two things make the 401(k) stand out. First, the contribution limits are substantially higher than IRAs. In 2025, you can contribute up to $23,500 in employee deferrals. In 2026, that rises to $24,500. If you're between 60 and 63, SECURE 2.0 introduced a "super catch-up" provision that lets you contribute an additional $11,250 on top of the standard catch-up — a detail almost no competitor article bothers to mention.

Second — and this is non-negotiable — most employers match some percentage of your contribution, typically 50 cents to a dollar for every dollar you put in, up to a cap (commonly 3–6% of your salary). If your employer matches 4% and you're contributing 2%, you're leaving roughly half your available match on the table. That's not a financial philosophy question. That's just arithmetic.

The downside of a 401(k) is that you're stuck with the investment menu your employer's plan administrator chose. Some plans are excellent; others are full of actively managed funds with expense ratios above 1% that will quietly eat thousands of dollars in returns over your career. If that's your situation, contributing enough to get the full employer match — and then directing additional savings elsewhere — is often the smarter move. You can explore how to build a diversified portfolio from scratch once you've secured that match.

Traditional IRA: the forgotten middle ground

An IRA — Individual Retirement Account — is something you open yourself, independent of your employer, at any brokerage you choose. You can hold almost anything in it: individual stocks, bonds, ETFs, index funds. The investment freedom is the point.

The traditional IRA works on the same pre-tax logic as a 401(k): contributions may be tax-deductible, the money grows tax-deferred, and you pay income tax when you withdraw. The catch is the contribution limit — just $7,000 in 2025 and 2026 (plus $1,000 catch-up if you're 50 or older), roughly a third of what you can put into a 401(k).

There's another catch that most explanations gloss over: if you or your spouse have access to a workplace retirement plan, the deductibility of traditional IRA contributions starts phasing out at relatively modest incomes. In 2025, a single filer covered by a workplace plan loses the deduction entirely above $89,000. For married couples where both have workplace plans, the phase-out starts at $126,000.

What this means in practice: if you have a 401(k) and earn a reasonable salary, the traditional IRA may not give you the tax deduction people expect. You're still contributing after-tax money, but you'll also owe tax on withdrawals — unlike a Roth, where post-tax contributions grow and come out completely tax-free. For many people in this situation, the traditional IRA ends up being the worst of both worlds, and a Roth IRA is the better call.

The one place where the traditional IRA shines: rollovers. When you leave a job, rolling your old 401(k) into a traditional IRA gives you far more investment control than leaving it in the old plan or moving it to your new employer. The ICI found that 59% of traditional IRA-owning households have rollover assets in them — most traditional IRAs are parked money from old jobs, not active savings vehicles.

Roth IRA: the account worth understanding properly

The Roth IRA has had a cultural moment. Younger households are gravitating toward it — and with good reason, though not always for the right reasons. The ICI found that Roth IRAs are owned by 26% of US households, with younger savers disproportionately represented. That trend reflects something real.

You contribute after-tax money. It grows completely tax-free. Qualified withdrawals in retirement are tax-free. No required minimum distributions during your lifetime — meaning if you don't need the money at 73, you don't have to take it out. You can pass it to heirs who also get tax-free withdrawals, which makes it a legitimate estate planning tool.

You can also withdraw your contributions (not earnings) at any time, penalty-free. This is different from every other retirement account and makes the Roth IRA arguably the most flexible tax-advantaged account available to most people. It's not technically an emergency fund, but for young savers who aren't sure they can lock money away for 40 years, that flexibility is psychologically significant.

The constraints: income limits. In 2025, single filers earning above $165,000 and married couples earning above $246,000 can't contribute directly to a Roth IRA. At those income levels, there's a workaround called the "backdoor Roth" — making a non-deductible traditional IRA contribution and immediately converting it. It's a legitimate strategy that most high earners with good financial planners use, though it requires careful execution to avoid unexpected taxes.

One thing worth saying plainly: the standard pitch for Roth IRAs — "pay taxes now so you don't have to later" — is correct in principle, but it depends entirely on where you sit in the tax brackets now versus retirement. If you're currently in the 22% or 24% bracket and you expect to be in the 12% bracket in retirement (which is realistic for many people whose income drops when they stop working), a traditional IRA or 401(k) may actually deliver a better mathematical outcome. Tax diversification — holding both pre-tax and Roth assets — is the conservative answer when you're genuinely uncertain.

The Roth is especially powerful if you're starting to invest in your 20s or early 30s: decades of tax-free compounding on money that was already taxed is genuinely valuable.

The order of operations most people get wrong

Here's the decision framework that most personal finance content either buries or omits entirely:

Step 1: Contribute to your 401(k) up to the full employer match. No exceptions. This is the closest thing to free money that exists in personal finance.

Step 2: Open a Roth IRA (if you're eligible) and max it out. The $7,000 limit is low enough that most working adults can hit it with some intention, and the flexibility and tax-free growth are hard to beat. This is where the investment freedom of an IRA — choosing a low-cost global index fund at Vanguard or Fidelity instead of whatever's in your employer's plan — actually matters. Understanding how index funds outperform most active strategies makes this step even easier to execute.

Step 3: Go back to your 401(k) and increase contributions up to the annual maximum. Once your Roth is funded, direct remaining savings back into the 401(k) for the higher limits and continued tax deferral.

Step 4: If you've maxed both, consider a taxable brokerage account. That's a conversation for another post.

This sequence prioritises free money first, flexibility second, and higher limits third. It's not the only valid approach — someone in the 32% bracket with stable income who expects to retire on far less might skip the Roth and go pre-tax throughout — but it works for the majority of people in the middle of their careers.

What this means for you right now

The three accounts aren't competitors. For most working people, they're a sequence: capture the match, fund the Roth, fill the 401(k). The account you use first is less important than actually using one — only about 16% of US households made an IRA contribution at all in tax year 2023, according to the ICI.

The one question worth sitting with: do you expect your tax rate to be higher or lower in retirement than it is today? If higher, lean Roth. If lower, lean pre-tax. If genuinely uncertain, do both and give yourself the flexibility to manage withdrawals strategically in retirement.

Everything else — the specific fund choices, the contribution percentage, the exact sequencing — matters far less than starting.