Both the 401(k) and the Roth IRA are tax-advantaged retirement accounts, but they work in almost opposite ways. A traditional 401(k) is offered through your employer, funded with pre-tax payroll deductions that lower your taxable income today, and often comes with a matching contribution — essentially free money. A Roth IRA is an account you open yourself, funded with money you've already paid tax on, and in exchange every dollar of growth comes out completely tax-free in retirement. The "right" account depends heavily on whether you expect to be in a higher or lower tax bracket when you retire, whether your employer offers a match, and how much flexibility you want over your investment choices.
Most financial advisors don't recommend picking just one — they're complementary, and using both gives you tax diversification for whatever future tax rates look like.
Side-by-Side Comparison
| Criteria | 401(k) (Traditional) | Roth IRA |
|---|---|---|
| Tax treatment | Pre-tax now, taxed on withdrawal | After-tax now, tax-free on withdrawal |
| 2026 contribution limit | $24,500 ($32,250 age 50+) | $7,500 ($8,600 age 50+) |
| Employer match | Often yes — free money up to a % | Never — it's an individual account |
| Income eligibility | No income limit to contribute | Phases out above ~$150K single / ~$236K married |
| Investment options | Limited to plan's fund menu | Almost unlimited — any brokerage, any fund |
| Early withdrawal flexibility | Penalty + tax before 59½ (with exceptions) | Contributions (not gains) withdrawable anytime, tax/penalty-free |
| Required minimum distributions | Yes at RMD age (unless Roth 401k) | None during the original owner's lifetime |
When to Prioritize the 401(k)
Prioritize 401(k) if…
- Your employer offers any match — always capture it first
- You're in a high tax bracket now and expect a lower one in retirement
- You want to contribute more than the Roth IRA's $7,500 limit allows
- You earn above the Roth IRA income phase-out and don't want to do a backdoor Roth
- You value automatic payroll deduction over manual contributions
Prioritize Roth IRA if…
- You're early career and in a relatively low tax bracket now
- You want tax-free income in retirement, with no RMDs
- You want more investment choice than your 401(k) plan offers
- You may need penalty-free access to contributions before 59½
- You've already captured your full employer match
Worked Example
Scenario: A 30-year-old earning $75,000, in the 22% tax bracket, with an employer offering a 50% match up to 6% of salary, contributing $500/month to retirement.
Contributing $500/month ($6,000/year, 8% of salary) to the 401(k) up to the 6% match threshold ($4,500/year) captures a $2,250/year employer match — an immediate 50% return that no Roth IRA can offer. The remaining $1,500/year could go to a Roth IRA instead. At a 7% average annual return over 35 years, the 401(k) match alone ($2,250/year growing) compounds to roughly $310,000 — money that exists purely because the employer matched it, on top of whatever the employee's own contributions grow to.
*Figures are illustrative estimates only, not financial or tax advice. Consult a financial advisor for your specific situation.
Frequently Asked Questions
What is the main difference between a 401(k) and a Roth IRA?
A 401(k) is pre-tax now, taxed on withdrawal. A Roth IRA is after-tax now, tax-free on qualified withdrawal, including growth.
Should I max out my 401(k) match before contributing to a Roth IRA?
Yes, almost always — an employer match is an instant, guaranteed return. Capture the full match first, then consider a Roth IRA.
What are the 2026 contribution limits?
401(k): $24,500 ($32,250 with catch-up). Roth IRA: $7,500 ($8,600 with catch-up), subject to income phase-outs.
Can I contribute to both a 401(k) and a Roth IRA?
Yes — they're independent accounts with separate limits, and using both gives tax diversification.
Are there income limits for a Roth IRA?
Yes, direct contributions phase out at higher incomes; high earners can use a backdoor Roth strategy. 401(k)s have no income limit.
Which is better if I expect a higher tax bracket in retirement?
A Roth IRA tends to win, since you pay tax now at a lower rate and withdraw tax-free later.
What happens to my 401(k) if I change jobs?
You can leave it, roll it into your new employer's plan, or roll it into an IRA via a direct trustee-to-trustee transfer.