Can my teenager's Roth IRA really turn a summer job into a huge retirement head start?

Yes, and the math is striking. A minor with earned income from a real job can fund a Roth IRA up to the lesser of their earnings or the annual IRS limit. Because contributions grow tax-free for decades, money invested in the teens has 40-plus years to compound. Even modest early contributions can dwarf larger amounts saved later, thanks to time. A parent can open a custodial Roth IRA and even gift the contribution as long as the child actually earned at least that much. Contributions can always be withdrawn tax- and penalty-free, so it's not fully locked up. This is one of the highest-return financial gifts you can give a working teenager.