Your job offered you free money. You said no.

Nobody explains the match at orientation. Here's what it is, what vesting really means, and the ten-minute fix.

Here's the sentence that should have been in your offer letter: "We will pay you extra money, but only if you save some of your own."

That's a 401(k) match. Your employer contributes to your retirement account in proportion to what you put in. The most common formulas look like this:

"100% match on the first 3% of salary." You contribute 3% of your pay, they add another 3%. That's a 100% return on your money before the market does anything at all.

"50% match on the first 6%." You contribute 6%, they add 3%. That's a 50% instant return.

Run the numbers on a $55,000 salary with a 50%-of-6% match. Your 6% is $3,300 a year. Their match is $1,650. Skip the contribution and you don't just lose the savings — you hand back $1,650 of compensation you already earned. Every year.

No investment on earth reliably pays 50 to 100 percent the moment you show up. This one does, and leaving it unclaimed is one of the most common money mistakes in the country.

Your own contributions are always yours. The employer's match may not be — yet. That's vesting.

Two structures to know:

Cliff vesting: you own 0% of the match until a set date, then 100% all at once. Federal law caps the cliff at three years.

Graded vesting: you own a growing percentage each year, fully vested within six years at most.

Why this matters to you specifically: early-career workers change jobs more than anyone. If your plan has a cliff and you leave a few months early, the entire match — every dollar your employer contributed — goes back to them. Before you accept a new offer, check your vesting date. Sometimes staying eight more weeks is worth four figures. Sometimes the new offer beats it anyway. But you cannot do that math if you never look.

Where to look: your plan's Summary Plan Description, or the vesting schedule page in your 401(k) portal. Ten minutes.

Many plans now offer both a traditional 401(k) and a Roth 401(k). Same account, different tax treatment.

Traditional: contributions go in before tax, lowering your taxable income today. You pay taxes when you withdraw in retirement.

Roth: contributions go in after tax. No break today — but qualified withdrawals in retirement are tax-free, growth included.

The plain-language rule of thumb: pay the tax when your rate is lowest. Early in your career, your income — and your tax bracket — is probably the lowest it will ever be. That tilts the answer toward Roth for many recent graduates: pay the small tax now, never pay tax on decades of growth.

One detail that surprises people: the employer match usually lands in the traditional bucket regardless of which you pick for your own money. Some plans now allow Roth treatment of the match, but don't assume yours does — check.

You picked a contribution rate, and then the portal showed you thirty funds with names like "Capital Appreciation Institutional Class R6." This is where most people freeze, pick nothing, and get defaulted into something they never look at again.

Good news: the default is usually fine. Most plans default to a target-date fund — a single fund labeled with a year near when you'd turn 65 (a "2065 fund" for a recent graduate). It holds a diversified mix and automatically gets more conservative as the date approaches. It is the rare financial product designed for people who don't want to think about it.

Check two things: that you're in the fund matching your rough retirement year, and its expense ratio — the annual fee. Many solid target-date funds charge a small fraction of a percent per year. If yours is creeping toward a full percent, that's worth a closer look.

You can get fancier later. Right now, captured match plus target-date fund beats a perfect portfolio you never set up.

The rule is simple: never leave the match on the table. It's the highest-return move available to you, full stop.