Roth vs Traditional

The two buckets, in one paragraph each

Traditional (401(k) or IRA): you skip the tax now (contributions come out of your paycheck before income tax) and the account grows untouched for decades. The bill comes due on the way out: every dollar you withdraw in retirement is taxed as ordinary income.

Roth: the mirror image. You pay tax on the money now, contribute what’s left, and then the account grows tax-free and comes out tax-free in retirement: no tax on decades of growth, and no required withdrawals during your lifetime.

Same investment inside either bucket. The only real difference is when the IRS gets paid.

The question that decides it

Strip away the noise and it comes down to one comparison: your tax rate today versus your tax rate in retirement.

• Expect a higher rate today than in retirement? Traditional wins: deduct at the high rate, withdraw at the low one.
• Expect a lower rate today (early career, a temporary income dip, a sabbatical year)? Roth wins: pay the small tax now, escape the bigger one later.
• Genuinely unsure? That’s most people, which is an argument for holding some of both, so future-you has options no matter what tax rates do.

For illustration: a family in the 32% bracket today who expects to draw retirement income in the 22% bracket keeps an extra 10 cents of every deferred dollar. Flip the brackets and the same move costs them 10 cents.

Why the answer changes over your career

This isn’t a decision you make once at 25 and never revisit. A common arc: Roth-heavy in your 20s and early 30s while your bracket is low; leaning traditional in your peak-earning 40s and 50s when the deduction is worth the most; then, sometimes, converting traditional money back to Roth in the low-income window between retiring and starting Social Security. (That last move is its own topic: see our Roth Conversions guide.)

Life events shift it too: a big raise, a spouse stepping back from work, a move between states with different income taxes. The right split follows your bracket around.

What people get wrong

• “Roth is always better because tax-free sounds better.” Tax-free later isn’t free. You paid the tax up front, possibly at your highest-ever rate.
• Ignoring the employer match. If your employer matches 401(k) contributions, that match beats every nuance on this page. Capture all of it first, in either bucket.
• Forgetting RMDs. Traditional accounts come with required withdrawals starting in your 70s, whether you need the money or not. Roth accounts don’t, which matters for taxes, Medicare premiums, and what you leave to your kids.
• Treating the balances as equal. $500,000 in a traditional account is not $500,000. Part of it belongs to the IRS. A Roth balance is all yours. Comparing them straight across overstates how far the traditional bucket goes.

Want to see the difference in dollars? Try the Taxable vs. Tax-Free Growth calculator.