401(k) match optimizer

401(k) match — the single best return in personal finance

If your employer offers a 401(k) match, contributing enough to capture the full match is mathematically the best financial move available to most American workers. A 100% match is an immediate 100% return on the dollar you contribute — before any market return compounds on top. This calculator shows exactly how much match you're leaving on the table and what that costs you at retirement.

How employer matching works

A 401(k) match is a formula the employer uses to add to your retirement account based on your own contributions. Common formulas:

• 100% of first 3% + 50% of next 2% — the classic "safe harbor" formula. Contribute 5% of salary, get 4% from employer, total 9% going to retirement.
• 50% of first 6% — older but still common. Contribute 6% of salary, get 3% from employer.
• 100% of first 6% — the most generous common formula. Contribute 6%, get 6%.
• Discretionary — employer decides each year based on profits. Common at small businesses and non-profits.

On a $85,000 salary with a 100%-of-first-6% match, the full match is $5,100/year. Missing that match for a year and investing at 7% for 30 years costs you about $38,800 in retirement value.

Why people miss their match

A surprising number of eligible workers don't capture their full match. Common reasons:

• Didn't enroll — default contribution is 0 unless auto-enrollment is set up. About 20% of eligible workers never enroll.
• Enrolled but set too low — default auto-enrollment is often 3%, below the 5–6% threshold for full match.
• Front-loaded contributions — some people try to max out early in the year. If the plan doesn't true-up, you miss match on paychecks where you hit the $23,000 IRS cap before year-end.
• Thought they couldn't afford it — but the employer match is typically 3–6% of salary of extra compensation. Walking away from that is a compensation cut.

The compound cost of skipping match

A single year of missed match at age 30 costs you ~$38,000 at age 65 (assuming 7% growth). A decade of missed match costs $430,000+ at age 65. This is why employer match is the single highest-leverage financial decision most young workers face.

The priority stack for extra dollars

The conventional advice for where to put each additional dollar of savings:

1. 401(k) to full employer match — 100% guaranteed return. Non-negotiable if match is offered.
2. Pay off high-interest debt — credit cards at 20%+ APR. Better than any investment return.
3. Fund HSA to the max — if eligible, triple-tax-advantaged (deductible going in, tax-free growth, tax-free withdrawals for medical).
4. Roth IRA to the max — $7,000/yr in 2024, tax-free growth forever.
5. Max out 401(k) — $23,000/yr in 2024 ($30,500 if 50+).
6. Taxable brokerage — once all tax-advantaged space is used.

Vesting — the catch

The match is "free money" only if you stay long enough to vest. Vesting schedules:

• Immediate vesting — some plans, especially safe-harbor plans, must vest match immediately.
• Cliff vesting — you get 0% until year 3 (or sometimes year 2), then 100%.
• Graded vesting — 20% per year for 5 years. At year 3 you're 60% vested.

If you're planning to job-hop every 18 months, check your vesting schedule before leaving. Waiting 6 more months at the existing job to cross a vesting cliff can mean $10k–$50k of preserved match.

True-up: the underappreciated feature

If your plan has a "true-up" provision, the employer recalculates match at year-end based on your full-year contribution. This means if you front-loaded and missed match on later paychecks, the employer makes it up in January. Most plans don't offer true-up, making contribution pacing matter. Ask HR whether your plan trues-up; if not, set your contribution percentage so you'll hit the IRS cap at year-end, not earlier.