The Key Difference: When You Pay Taxes
The fundamental difference is simple: a 401(k) gives you a tax break now (contributions are pre-tax), while a Roth IRA gives you tax-free withdrawals in retirement (contributions are after-tax).
Side-by-Side Comparison
| Feature | 401(k) | Roth IRA |
|---|---|---|
| 2026 Contribution Limit | $24,500 | $7,500 |
| Catch-Up (50+) | +$8,000 | +$1,100 |
| Tax Treatment | Pre-tax (deductible) | After-tax (tax-free growth) |
| Employer Match | Yes (free money!) | No |
| Required Min. Distributions | Yes, at age 73–75 | No (lifetime) |
| Income Limits | None | $153K single / $242K married |
| Early Withdrawal Penalty | 10% + income tax | Contributions: penalty-free |
Under the SECURE 2.0 Act, RMD age is 73 for those born 1951–1959 and 75 for those born 1960 or later.
The Optimal Strategy: Use Both
For most Americans, the best approach is a three-step strategy:
Step 1: Contribute enough to your 401(k) to get the full employer match — this is literally free money with an instant 50–100% return.
Step 2: Max out your Roth IRA ($7,500 in 2026) for tax-free growth and withdrawal flexibility.
Step 3: Go back and max out the remaining 401(k) space if you can afford it.
When to Prioritize a 401(k)
Choose the 401(k) when you're in a high tax bracket now (32%+) and expect to be in a lower bracket in retirement, when your employer offers generous matching, or when you've already maxed out your Roth IRA.
When to Prioritize a Roth IRA
Choose the Roth IRA when you're early in your career with a lower income, when you expect tax rates to rise in the future, when you want flexibility to access contributions penalty-free, or when you want to avoid Required Minimum Distributions.
The Power of Starting Early
A 25-year-old investing $500/month in a Roth IRA at 7% average returns will have approximately $1.2 million tax-free at age 65. Use our passive income calculator to model your specific scenario.