When my own teenager put her first babysitting money into an index fund, she wasn't chasing riches — she was buying time. That's the real gift here: a decade-plus head start that money simply can't buy back later. Here's the parent-to-parent walkthrough I wish someone had handed me.
If there's one thing I'd tattoo on the arm of every parent (mine included), it's this: for a teenager, time is the single biggest advantage they will ever have as an investor, and it's the one asset that quietly disappears with every year we wait. A 15-year-old who starts today has a runway most adults would trade a lot of money to get back.
The engine behind that head start is compound interest — the plain fact that money invested earns returns, and then those returns earn returns too. It starts slow and looks almost pointless in year one. Then it snowballs. Consider a rough, illustrative example: a teen who invests just $50 a month from age 15, at a hypothetical average return, can end up with dramatically more by retirement than someone who starts the exact same habit at 30 — not because they invested more money, but because their money had fifteen extra years to grow. Waiting isn't neutral; it's expensive.
The good news for us as parents is that the "how" is far simpler than it sounds. You don't need to be an expert or hand over a fortune. You mostly need to open the right kind of account and help your teen start small and stay consistent. Let's look at the two accounts that actually make sense before 18.
Because your teen is under 18, they can't legally open a brokerage account on their own. That's where custodial accounts come in — you (the adult) open and manage it on their behalf.
| Account type | Best for | Key rule |
|---|---|---|
| Custodial brokerage (UTMA / UGMA) | General investing when your teen has no job — birthday money, gifts, allowance, savings. | No earned-income requirement. The money legally becomes the child's, and control transfers to them at the age of majority (18–21+, depending on your state). |
| Custodial Roth IRA | A working teen who wants a tax-advantaged retirement head start. | The teen must have earned income, and contributions can't exceed what they earned that year (up to the annual IRS limit). Qualified withdrawals in retirement are tax-free. |
| Regular (individual) brokerage | Not available to minors. | Your teen can open their own standard account once they turn 18 — until then, use a custodial account. |
Here's how I think about the choice. A UTMA/UGMA custodial brokerage is the flexible, no-strings option — perfect if your teen doesn't have a paycheck yet but has some birthday or gift money to put to work. A custodial Roth IRA is the powerhouse for a teen who earns money, because decades of tax-free growth on retirement money is hard to beat. Plenty of families use both: the Roth for earned income, a UTMA brokerage for everything else. Neither one requires you to pick individual stocks or watch the market — more on that below.
The whole thing is usually a 15-minute online form. Here's the order I'd go in.
Does your teen have earned income and want a retirement head start? Lean toward a custodial Roth IRA. Just have gift or savings money to invest? A UTMA/UGMA custodial brokerage fits. Many families open both — one for earned income, one for everything else.
Choose a reputable, low-cost broker that clearly offers custodial accounts. Look for no account minimum, no monthly fee, and commission-free index funds and ETFs. Most major brokerages have a straightforward "custodial" or "youth" account application online.
Have both of your details handy: Social Security numbers (yours and your teen's), dates of birth, addresses, and a bank account to link for funding. For a Roth IRA, jot down roughly what your teen earned this year so you don't over-contribute.
Link your bank and make a first transfer — even $25 or $50 is a fine start. Consider setting up a small automatic monthly contribution; consistency beats size every time. For a Roth, remember the ceiling is whatever your teen earned, up to the annual limit.
Cash sitting in the account isn't invested yet — you have to buy something. Keep it boring and broad: a low-cost index fund or total-market ETF spreads the money across hundreds of companies in one click. No stock-picking required.
This is where parents tend to overthink it, so let me make it easy: for a beginning teen investor, simple and cheap wins. You do not need to research hot stocks or time anything. A single low-cost, broad-market index fund — one that holds a slice of hundreds or thousands of companies — gives you instant diversification and historically strong long-term returns, all for a tiny fee.
The reason I steer my own kid toward index funds instead of individual stocks is risk. Betting on one company is a coin flip; owning a broad slice of the whole market means no single company can sink the ship. Pair that with the teen's enormous time horizon and you've got a genuinely powerful, low-maintenance setup. If you want to go deeper on the mechanics, our guide to investing for teenagers and the broader investing hub break it down in teen-friendly terms you can read together.
One more thing worth doing: let your teen actually watch it. Even a tiny balance that dips and recovers teaches more about markets — and about staying calm — than any lecture I could give.
It depends on the account. A custodial brokerage (UTMA/UGMA) legally belongs to the child, and control transfers to them at your state's "age of majority" — often 18, but sometimes 21 or later depending on the state and how the account was set up. At that point they can do whatever they like with it. A custodial Roth IRA generally converts to a standard Roth IRA in the teen's name once they're an adult. Check the specifics with your brokerage, since the transfer age varies by state.
They need earned income, which is broader than a formal W-2 job. Babysitting, lawn mowing, tutoring, or a summer paycheck all count. What doesn't count is allowance, birthday money, or investment gains. You can only contribute up to what they earned that year, capped at the annual IRS limit. If your teen has no earned income at all, a UTMA/UGMA custodial brokerage is the better fit — it has no earned-income requirement.
Less than you'd think. Many brokerages have no minimum, so you can literally begin with $25 or $50. Honestly, the dollar amount matters far less than the habit — a small automatic monthly contribution builds both the balance and the discipline. Start with what's comfortable and let time do the heavy lifting.
Yes — the money doesn't have to be the exact dollars your teen earned. A popular move is for a parent or grandparent to "match" what the teen made, so the teen can spend their paycheck while the family funds the Roth. The catch is the same hard limit: total contributions still can't exceed what the teen earned that year (or the annual cap, whichever is lower). Confirm the details with your brokerage or a tax professional.
There can be, and the rules differ by account. Investment income in a custodial brokerage can trigger tax reporting once it passes certain thresholds, while a Roth IRA grows tax-free and qualified retirement withdrawals aren't taxed. The specifics depend on your family's situation, so this is exactly the kind of thing worth confirming with a tax professional rather than guessing.