Roth 401(k) or Roth IRA? Both grow tax-free. The differences are in the limits, the income rules, and how easily you can reach your money.
Written for employees and business owners deciding where their Roth dollars should go, including S-corp owners with a Solo 401(k).
The short answer
A Roth 401(k) and a Roth IRA follow the same basic idea: you pay tax on the money now, and qualified withdrawals in retirement are tax-free. They have separate limits, so you don’t have to choose. You can fund both in the same year.
That’s $24,500 through a Roth 401(k) plus $7,500 in a Roth IRA, for someone under 50. The Roth 401(k) holds more. The Roth IRA is more flexible. Most people get the most out of using them together.
Side by side
| Roth 401(k) | Roth IRA | |
|---|---|---|
| Where you get it | Through an employer’s plan, or your own Solo 401(k) | Any brokerage, opened by you |
| 2026 limit | $24,500, shared with traditional 401(k) deferrals | $7,500, shared with traditional IRAs |
| Catch-up at 50+ | +$8,000 (+$11,250 at ages 60–63) | +$1,100 |
| Income limit | None | Phases out at $153,000–$168,000 single, $242,000–$252,000 married filing jointly |
| How you contribute | Payroll deduction only | Any transfer from your bank |
| Deadline for 2026 | Paychecks dated by December 31, 2026 | Tax filing deadline, April 15, 2027 |
| Employer money | Possible, like a match or profit-sharing | No |
| Investment choices | The plan’s menu | Almost anything |
| Taking money out early | Each withdrawal includes a share of earnings, if the plan allows one at all | Contributions come out first, anytime, tax- and penalty-free |
| Required distributions | None during your lifetime (since 2024) | None during your lifetime |
| Loans | Only if the plan allows them | Not available |
| Rollovers | Can roll into a Roth IRA later | Can’t roll into a 401(k) |
The biggest difference: getting to your money early
Life happens before 59½. Here’s what it looks like to take out $10,000 from an account with $20,000 in it: $15,000 of your contributions plus $5,000 of earnings.
The $10,000 comes entirely from your contributions, because the IRS treats those as coming out first. No tax, no penalty.
The $10,000 comes out in proportion: $7,500 of contributions and $2,500 of earnings. The $2,500 is taxed and usually hit with a 10% penalty, about $990 at a 29.5% combined tax rate.
Hypothetical example. Many 401(k) plans don’t allow withdrawals at all while you still work for the employer, which makes the Roth IRA even more flexible by comparison.
The five-year clocks
To withdraw earnings tax-free, you need to be 59½ and have had a Roth account for at least five years. The two accounts keep separate clocks.
- Roth IRA: one clock covers all your Roth IRAs. It starts on January 1 of the year of your first contribution.
- Roth 401(k): each plan has its own clock, starting with your first Roth contribution to that plan.
- The tip: open a Roth IRA early, even with a small amount. If you roll a Roth 401(k) into it years later, the money uses the Roth IRA’s older clock.
Using both: where the money flows
a bank transfer
optional rollover
Which to fund first
1. Any match
Contribute enough to the 401(k) to get the full match. It’s an instant return.
2. Roth IRA
The most flexible Roth dollars, with any investment you choose.
3. Back to the 401(k)
Add more through payroll, Roth or traditional, depending on your bracket.
If your income is over the Roth IRA limit, skip step 2. The Roth 401(k) has no income limit, and some higher earners use a “backdoor” Roth IRA, which is worth reviewing with a tax advisor first.
For S-corp owners with a Solo 401(k)
- K-1 profit doesn’t count for a Roth IRA. IRA contributions are limited to your earned compensation, and for an S-corp owner that means W-2 wages, not distributions.
- A Roth deferral keeps your IRA room. It doesn’t reduce W-2 Box 1, while a traditional deferral does, which can shrink how much you can put in your own Roth IRA.
- Married? Your spouse’s wages can count. Filing jointly, the spousal IRA rule lets a working spouse’s pay support IRA contributions for both of you.
- The employer side stays separate. The S-corp’s profit-sharing contribution goes into the 401(k), often pre-tax, and doesn’t touch either Roth limit.
Quick decision guide
- Want access in an emergency: Roth IRA first
- Want to save more than $7,500: add the Roth 401(k)
- Income over the Roth IRA limit: Roth 401(k)
- Want the widest investment choice: Roth IRA
- Employer match on the table: 401(k) first
- Open a Roth IRA early to start its clock
- S-corp owner: check W-2 Box 1 for IRA room
- Roll the Roth 401(k) into a Roth IRA later
Want help splitting your Roth dollars?
We’ll check your Roth IRA eligibility, your W-2 and spousal options, and how much to send to a Roth 401(k), Roth IRA, or both this year.
Or call 516-261-2171
Sources
This article is for general educational purposes and is not individual investment, tax, or legal advice. The withdrawal example is hypothetical and simplified; actual tax and penalties depend on your situation and any exceptions that apply. Roth withdrawals are tax-free only when qualified. Limits and income ranges shown are for 2026.