Retirement Accounts and Tax Drag

The Wrapper Matters as Much as What's Inside It

Two students each invest $6,000 a year in the exact same index fund for 40 years, earning the exact same return. One of them ends up with meaningfully more money — not because they picked better investments, but because of the account they used. That's the part of investing nobody teaches until it's almost too late to fully use: the tax treatment of the account you invest through can matter as much as what you put in it.

Most brokerage accounts are taxable by default — you owe capital gains tax when you sell, and tax on dividends every year even if you never sell anything. Retirement accounts exist specifically to change that deal.

Traditional vs. Roth: Pay Taxes Now or Later

The two main flavors of retirement account differ in exactly one place: when the IRS gets paid.

• Traditional (401(k) or IRA): contributions go in before tax — they lower your taxable income the year you make them. The money then grows completely untaxed, and you pay ordinary income tax only when you withdraw it in retirement.
• Roth (401(k) or IRA): contributions go in after tax — no deduction today. But the money then grows completely untaxed, and withdrawals in retirement are entirely tax-free, growth included.

The rule of thumb: Roth tends to win if you expect to be in a higher tax bracket later than you are today — which describes almost every high schooler with a summer job. You're very likely in the lowest tax bracket you'll ever be in right now, which makes paying tax today, while it's cheap, and never again, the better trade for a lot of young investors. A custodial Roth IRA can be opened for a minor with earned income (a job, not allowance) well before you'd ever open a normal brokerage account.

Tax Drag: The Cost of the Wrong Wrapper

"Tax drag" is what happens to a taxable account's return every year the IRS takes a cut of dividends and realized gains — money that, in a retirement account, would have kept compounding instead. It doesn't feel dramatic in any single year. Over 40 years, it adds up to a real gap.

Employer Matching: The Only Guaranteed Return in Investing

If a job offers a 401(k) match — say, the employer adds 50 cents for every dollar you contribute, up to 6% of your salary — that match is an instant, guaranteed 50% return the moment it lands, before the money has even been invested in anything. No stock, no strategy, nothing else in this entire curriculum offers a guaranteed return like that. Contributing at least enough to capture the full match, before optimizing anything else, is close to universal advice among people who study this for a living.

Contribution Limits Exist for a Reason

Because these accounts are so tax-advantaged, the IRS caps how much can go in each year — the limits change periodically and are worth checking directly rather than memorizing, since this lesson would go stale the moment they update. The caps matter less at your first job than the habit does: contributing consistently, even in small amounts, for the extra decade a high schooler has over someone starting at 28 is worth more than almost any later catch-up contribution could recover.