GUIDE · MONEY · RETIREMENT
Roth 401(k) vs Roth IRA: Where Should Your Next Dollar Go?
Here’s the secret the comparison hides: a Roth dollar is a Roth dollar. $1,000 in a Roth 401(k) and $1,000 in a Roth IRA grow identically and withdraw identically — the tax treatment is the same because the tax treatment is the account type, not the account. So the real question isn’t “which account is better” — it’s “which dollar goes where first.” At the worked example — $90,000 salary, $15,000 a year to save, a 50%-to-6% employer match, 7% returns, 30 years — the answer is $5,400 → Roth 401(k) (captures the full $2,700 match), $7,500 → Roth IRA (the full 2026 limit), then $2,100 → back to the Roth 401(k): $114,184 of tax-free growth, with the match alone worth $16,031 after-tax. Below: the 60-second rule, how each account really works, the 2026 limits, the worked example line by line, the income trap, and the mistakes that cost real money.
The 60-second rule
Roth 401(k) to the full match → Roth IRA to the limit → back to the Roth 401(k). That order captures the only free money in the system first (the match), then buys the best fund choice and flexibility (the IRA), then uses the biggest ceiling (the 401(k)) for everything left. Run your own numbers in the Roth 401(k) vs Roth IRA calculator with your actual salary, your real match formula from the benefits portal, and the savings number from your budget — not your aspirations. If you earn over $168,000 single ($252,000 joint), step two needs the backdoor Roth workaround below. Everything below is the evidence for that rule.
How a Roth 401(k) really works
A Roth 401(k) lives inside your employer’s plan. You contribute after-tax dollars from your paycheck — no deduction today — and qualified withdrawals in retirement are completely tax-free, growth included. Its superpowers are scale and access: a $24,500 ceiling in 2026 (over triple the IRA), no income limits whatsoever, and the employer match — typically fifty cents to a dollar per dollar on the first few percent of your salary. Its weaknesses: you can only buy your plan’s fund menu (sometimes excellent, sometimes a 1%-fee wasteland), and withdrawals before 59½ face plan rules. Since SECURE 2.0, there are no required minimum distributions on the Roth side — one less reason the IRA used to win.
How a Roth IRA really works
A Roth IRA is yours alone — no employer required. Same tax deal: after-tax dollars in, tax-free qualified withdrawals out. Its superpowers are freedom and flexibility: buy anything (any fund, any stock, any ETF at any brokerage), and withdraw your contributions anytime, tax- and penalty-free, for any reason — it doubles as a stealth emergency fund. Its weaknesses: a $7,500 ceiling in 2026, and the income phase-out (singles $153,000–$168,000, joint filers $242,000–$252,000) that locks high earners out of direct contributions entirely. No match, no loans — IRAs can never be borrowed against.
The 2026 limits that decide it
Per IRS Notice 2025-67. The two numbers that matter most are $24,500 and $7,500 — and the phase-out that can zero out the second one:
| 2026 figure | Roth 401(k) | Roth IRA |
|---|---|---|
| Contribution limit (under 50) | $24,500 | $7,500 |
| At 50+ (catch-up) | $32,500 | $8,600 |
| At 60–63 (super catch-up) | $35,750 | — |
| Income limit | None | Phases out $153k–$168k single / $242k–$252k joint |
| Can you max both? | Yes — $32,000 combined under 50, plus the match (total additions cap $72,000) | |
The $5,400 / $7,500 / $2,100 worked example, line by line
$90,000 salary (single), $15,000 a year to save, 50%-to-6% match, 7% returns, 30 years, 22% tax. Watch where each dollar lands:
Step 1 — $5,400 → Roth 401(k). Six percent of $90,000 is $5,400: exactly the contribution that captures the full match. The employer adds $2,700 (50% of $5,400) — an instant 50% return. Nothing in step two or three can beat free money, so the 401(k) goes first even though its fund menu is worse.
Step 2 — $7,500 → Roth IRA. $15,000 − $5,400 = $9,600 remains. $90,000 of income sits well under the $153,000 phase-out, so the full $7,500 2026 IRA limit is available — and it buys unlimited fund choice plus withdraw-your-contributions-anytime flexibility that the 401(k) can’t match.
Step 3 — $2,100 → back to the Roth 401(k). $2,100 remains, and the 401(k) still has $19,100 of its $24,500 ceiling left. The IRA is full; the 401(k) is the only Roth room remaining. Nothing overflows to taxable.
The payoff: $15,000 of Roth contributions × 1.0730 (7.6123) = $114,184, entirely tax-free. And the match: $2,700 a year × 7.6123 × (1 − 22%) = $16,031 after-tax — the match dollars are pre-tax, so they’re haircut at withdrawal. Notice the match is worth more than the entire IRA step. That’s why it goes first, every time.
The income trap (and the backdoor)
Earn over $168,000 single / $252,000 joint and step two vanishes: direct Roth IRA contributions are prohibited. Between $153,000–$168,000 ($242,000–$252,000 joint) it phases out linearly — at $160,500 single you get exactly half the $7,500. The workaround is the backdoor Roth: contribute $7,500 to a traditional IRA (nondeductible at that income), then convert it to Roth. Conversions have no income limit. One gotcha: the pro-rata rule — if you hold pre-tax money in any traditional IRA, the conversion is partly taxable. High earners with clean (empty) traditional IRAs get the cleanest backdoors. The Roth 401(k), meanwhile, never cares about your income: it’s the back door that never closes.
The match is pre-tax (yes, really)
This surprises everyone: matching dollars land in the pre-tax bucket even when your contributions are 100% Roth. SECURE 2.0 lets plans offer Roth matching, but few do yet. You’ll owe ordinary income tax when you withdraw the match dollars — which is why the calculator values the $2,700-a-year match at $16,031 after-tax rather than its $20,553 pre-tax future value. You still want it — a haircut on free money is still free money — but don’t count it as Roth dollars. Related 2026 fine print: if your 2025 wages topped $150,000, any catch-up contributions in 2026 must be Roth (SECURE 2.0) — your plan needs a Roth option for you to catch up at all.
Three mistakes to avoid
- Funding the IRA before capturing the full match. The most expensive ordering error: every unmatched dollar leaves fifty cents to a dollar of free money behind. A 50%-to-6% match you half-capture costs $1,350 a year — $10,000+ of retirement wealth per year of the mistake. Match first, always.
- Assuming you’re locked out at high income. The direct Roth IRA phases out, but the Roth 401(k) has no income limit and the backdoor Roth has no income limit on conversions. High earners often have more Roth room than anyone — $24,500 plus a $7,500 backdoor — not less.
- Ignoring a terrible 401(k) menu after the match. A 1%-a-year fee drag on a $100,000 balance is $1,000 a year, compounding against you for decades. Capture the match, then let the IRA’s unlimited menu do the heavy lifting; only return to the 401(k) when the IRA ceiling fills. Fund choice is a real cost.
Bright Side Kit. "Roth 401(k) vs Roth IRA: The 2026 Order." https://brightoolbox.com/guides/roth-401k-vs-roth-ira/ Accessed October 23, 2026.Frequently asked questions
Should I max the Roth IRA before putting anything in the 401(k)?
Only after you’ve captured the full employer match. The match is an instant 50–100% return; no fund’s expense ratio is low enough to beat free money. Order: 401(k) to the match → Roth IRA to $7,500 → back to the 401(k). The calculator shows your exact split.
What’s the backdoor Roth, exactly?
Two legal steps: (1) contribute $7,500 to a traditional IRA (you won’t deduct it at high income), then (2) convert it to a Roth IRA. Conversions have no income limit, so the phase-out doesn’t apply. Keep it clean: the pro-rata rule taxes the conversion proportionally if you hold pre-tax money in any traditional IRA.
Roth 401(k) or traditional 401(k) — which one?
That’s the tax-timing question, separate from this comparison: Roth wins if your marginal rate will be higher in retirement (young, early career, expecting raises); traditional wins at peak earnings. Our Roth vs Traditional 401(k) guide models it head to head with your numbers.
Can I withdraw Roth 401(k) money early like Roth IRA contributions?
Not as freely. Roth IRA contributions come out anytime, tax- and penalty-free. Roth 401(k) withdrawals follow plan rules — usually separation from the employer or age 59½ — and earnings withdrawn early face tax plus the 10% penalty unless an exception applies. The 5-year rule applies to both.
Do I still need a Roth IRA if my 401(k) has great funds?
Probably yes, for the flexibility: withdraw contributions anytime, no RMDs ever (the 401(k) Roth side lost its RMDs in 2024 too, so that gap closed), and an account that follows you through every job change. At $7,500 a year it’s cheap optionality — keep it even when the 401(k) menu is excellent.