Roth IRA vs 401(k): The Real Difference (And Which to Pick First)

Roth IRA. 401(k).
Both shelter your investments from taxes.
Both are powerful retirement accounts.
But they work in opposite directions — and picking the wrong one first can cost you $50K+ over a career.

The fundamental difference

Traditional 401(k): contributions are tax-free now. You pay taxes when you withdraw in retirement.

Roth IRA: contributions are taxed now. You pay zero taxes when you withdraw in retirement.

Same growth in between. Different tax timing. The choice depends on one question: will you be in a higher or lower tax bracket in retirement?

The simple rule for young investors

Most people in their 20s are in the lowest tax bracket they will ever be in. Their income is low. Their tax rate is 10-22%. By retirement, they will likely be in a higher bracket — or tax rates will have risen.

For young investors, Roth almost always wins. Pay the small tax now. Get tax-free growth and tax-free withdrawals for life.

The actual numbers

You contribute $7,000/year to a Roth IRA from 25 to 65. Average return: 8%. You contributed $280,000 total.

$430,000 difference — purely from picking Roth over Traditional. That is the single most valuable account decision a young investor can make.

What about the 401(k)?

The 401(k) is not bad. It is just different.

• Always contribute enough to get your employer match — that is free money, often a 100% return on day one.
• Beyond the match, prioritize the Roth IRA until you max it ($7,000/year in 2024).
• Then come back to the 401(k) with extra contributions.

The smart contribution order

1. 401(k) up to employer match — never leave free money.
2. Max Roth IRA — $7,000/year. Tax-free growth for life.
3. HSA if eligible — triple tax advantage. The most powerful account in finance.
4. Back to 401(k) — up to $23,000/year limit (2024).
5. Taxable brokerage account — for anything beyond.

The two situations where Traditional 401(k) wins

1. You are in the 32%+ tax bracket today. The current tax savings are too valuable to skip. Take the Traditional deduction now.

2. Your employer offers a Roth 401(k). You can have both Roth tax treatment AND the higher 401(k) contribution limit. Best of both worlds.

What if you have already been doing it "wrong"?

If you have been contributing to a Traditional 401(k) for years, you can do a Roth conversion in a low-income year. You pay tax on the conversion now in exchange for tax-free growth forever after. Most early-career professionals can convert tax-efficiently during a sabbatical or job transition.

Run your own retirement numbers — your contribution rate, your tax bracket, your timeline — and see exactly how much more you keep with the right account choice.