401(k) Match: The Return You Forfeit Under 6%

Payroll opens a benefits window every November, and the 401(k) line already has a number in it: 3%. It has said 3% since the day you were hired, because 3% was the default the plan administrator picked and nobody has touched it since. The match formula on the same screen says 50% up to 6%.

Those two numbers do not agree, and the disagreement has a price. On a $70,000 salary it is $1,050 a year — employer money you were offered, declined, and will not be offered again for that year. Contribute 6% and the company pays $2,100. Contribute 3% and it pays $1,050. The other $1,050 goes nowhere; it is simply not spent.

That is the answer. Everything below is the arithmetic, at your salary, under your plan’s formula, plus the several ways the tidy version breaks.

What “50% up to 6%” actually pays

The formula has two moving parts and people usually only read one of them. The 50% is the rate: the employer adds fifty cents for every dollar you defer. The 6% is a ceiling on your contribution, not on theirs. Once your own deferrals pass 6% of pay, the employer stops counting.

So the maximum the company will ever pay under this formula is 3% of salary. Half of six.

Take the $70,000 earner sitting at 3%. Their own money in is $70,000 × 0.03 = $2,100. The employer matches half of that, $1,050. The cap they could have reached was $70,000 × 0.06 × 0.50 = $2,100. They collect $1,050 and forfeit $1,050.

The forfeited half is the interesting number. It was never taxed, never earned, and does not carry over. A plan year closes and the unclaimed match closes with it.

The forfeit at your salary

Every cell below is salary × (6% − your rate) × 50%, floored at zero. Find your row, then your column.

One structural point hides in that grid. The marginal value of your fifth percentage point is identical to the value of your first: fifty cents on the dollar. The match does not taper as you approach the cap. It is flat, flat, flat, then it falls off a cliff to zero. Nothing about the sixth percent is worth less than the second.

What $1,050 a year turns into

Hold the $70,000 earner at 3% for thirty years and invest each year’s forfeited $1,050 at 6%, compounded annually, deposited at year end. The future value factor for a 30-year ordinary annuity at 6% is 79.058. So $1,050 × 79.058 = $83,011.

Stretch the same shortfall over a full career and the number stops being abstract. At forty years the factor is 154.762, so the total is roughly $162,500. That is not the size of anyone’s retirement shortfall. It is only the part that was handed over and returned.

Shorter horizons, same $1,050: about $13,800 after ten years (factor 13.181) and $38,600 after twenty (factor 36.786). Scale linearly for other salaries, because the forfeit is a fixed 1.5% of pay. Someone at $30,000 forfeits $450 a year and ends the thirty years about $35,600 short. Someone at $150,000 forfeits $2,250 and ends about $177,900 short.

Every one of those figures rests on assumptions worth saying out loud, because changing any of them changes all of them. Salary is flat — no raises, which understates the real forfeit rather than overstating it. Growth is a smooth 6% nominal, which no market has ever actually delivered on schedule. No fees are deducted, though a 0.5% expense ratio alone cuts the thirty-year figure by roughly 8%, from $83,011 down to about $76,000. The match is assumed fully vested the day it lands. And the dollars are nominal, so $83,011 in thirty years buys less than $83,011 buys today.

You can rebuild any of these yourself. The SEC’s compound interest calculator on Investor.gov takes an annual contribution, a rate and a number of years, and will reproduce every figure in this section — and, more usefully, let you swap 6% for something you believe more.

Not every formula that sounds generous is generous

Match formulas are written to sound large. A plan advertising a 12% threshold sounds like a bigger employer commitment than one capped at 3%. Often it is the reverse.

Here is what five common formulas actually pay, at the same $70,000 salary, across contribution rates.

Read the first two columns against each other. Below 6%, dollar-for-dollar-to-3% pays more than 50%-to-6%. At exactly 6% they tie at $2,100, and above 6% they tie forever. The higher threshold is only worth having if you reach it.

The 25%-to-12% column is the one that misleads. It caps at exactly 3% of salary — identical to the 50%-to-6% plan — but demands twice as much of your own money to get there.

What matters for a decision is the instant credit on the next dollar you defer, and that is set entirely by the rate, not the threshold. Dollar-for-dollar formulas pay 100% on each marginal dollar below the cap. Fifty percent formulas pay 50%. Quarter formulas pay 25%. Above the cap, every one of them pays 0%. Not “less”. Zero. That cliff is the single most important number in your plan document.

What reaching the cap costs per paycheck

Closing a 3-point gap on $70,000 means deferring another $2,100 a year. Biweekly, across 26 pay periods, that is $80.77 more per paycheck to go from 3% to 6%. The full 6% deferral is $161.54 a paycheck.

That figure is gross. Traditional 401(k) contributions come out pre-tax, so take-home falls by less than the deferral. At a 22% marginal federal rate, a $161.54 gross deferral reduces net pay by about $126, before any state tax. Check your own bracket before leaning on that number.

For other salaries the maths is the same shape: 6% of pay divided by 26. At $50,000 that is $115.38 a paycheck. At $100,000, $230.77. At $160,000, $369.23.

Two things people get wrong

“The match is a 50% return, so it beats the market.” Half right, and the wrong half matters. It is a one-time 50% credit on the dollar you contribute, in the year you contribute it. Not 50% a year.

Our $70,000 earner at 6% puts in $4,200 and the employer adds $2,100. The $4,200 becomes $6,300 the moment it lands. From that day forward the whole $6,300 grows at whatever the market does. The credit is enormous — nothing in year one reliably competes with an instant 50% — but it happens once. The match advantage stays a constant 50% of your own balance forever after; it grows in dollars, never in ratio. Calling it an annual rate of return is the error.

“I’ll contribute more later, when I earn more.” The arithmetic is unkind. Take two people at $70,000 who both end up at 6% and both stop at year 30. One goes to 6% immediately, collecting $2,100 of match every year: $63,000 of employer money, worth $166,022 at year 30. The other stays at 3% for a decade before switching: $10,500 of match in the first ten years plus $42,000 in the last twenty, $52,500 total, worth about $121,600.

The ten-year delay cost $10,500 in forgone match and about $44,400 in ending value. The gap is four times the missed money, because the earliest dollars are the ones with three decades of runway underneath them.

When these numbers break

Several situations invalidate the tables above, and a couple invalidate them badly.

You’re not vested. Plans commonly use graded vesting (20% a year over five years) or cliff vesting (nothing until year three, then everything). Leave before the schedule completes and the unvested match is forfeited back to the plan. Someone who quits at month 35 under a three-year cliff collects $0 of match no matter what any table says. Your summary plan description states the schedule; nothing else does.

Your plan has no true-up. Match is usually calculated per paycheck, not annually. Front-load your deferrals, hit the IRS elective deferral limit in September, and a plan without a true-up provision simply stops matching for the rest of the year — you get nine months of match instead of twelve. Plans with a true-up correct the shortfall after year end.

You’re a highly compensated employee. Nondiscrimination testing can force a refund of part of your deferral, and the match attached to it, after the year closes. This bites hardest at employers where lower-paid staff barely participate.

Your pay exceeds the plan compensation limit. The IRS caps how much compensation can be considered for plan purposes. Above that cap the match stops growing with salary, so the high-salary rows in the first table are an upper bound rather than a promise.

The match arrives as employer stock. Some plans still do this. Your job and your savings then move together, which is a different risk profile from a diversified fund holding the same dollar value.

Returns aren’t 6%. This is the largest lever in the entire model. At 4%, the $1,050-a-year thirty-year figure falls from $83,011 to about $58,900. At 8% it rises to about $118,900. Identical contributions, wildly different endings — and real sequences of returns are lumpy, so a bad first decade produces a different outcome from the same average arriving in a different order.

What this doesn’t tell you

None of this says whether contributing more is right for your situation. Someone carrying credit card debt at 24% is weighing the match against a guaranteed 24% cost of carry, and that comparison is not the one made here. Someone with no cash buffer is weighing it against the odds of a forced early withdrawal, which brings a 10% penalty plus income tax.

Taxes are barely modelled at all. Traditional deferrals cut taxable income now and are taxed at withdrawal; Roth deferrals invert that. Employer match is generally pre-tax whichever bucket your own money goes into, though some plans now permit Roth match. Which is better depends on your marginal rate now against your marginal rate decades from now, and nobody knows the second one.

Nor does any of it account for your plan’s fund menu. A plan charging 1.2% all-in is a materially different proposition from one charging 0.15%, and the fee compounds against you in exactly the way the match compounds for you.

FAQ

How much do I lose if I contribute 3% instead of 6%?

Under a 50%-up-to-6% formula you forfeit 1.5% of salary each year. At $50,000 that is $750, at $80,000 it is $1,200, at $150,000 it is $2,250. Compounded at 6% over thirty years those become roughly $59,300, $94,900 and $177,900.

Is the employer match really a 100% return?

Only on a dollar-for-dollar formula, only below the cap, and only in the first year. Put $2,000 into a 100%-up-to-4% plan and you hold $4,000 the same day. In year two that $4,000 grows at market rates, not another 100%. It is a one-time credit, not an annual rate.

What happens to the match if I leave my job after two years?

Depends entirely on vesting. Under three-year cliff vesting you keep none of it. Under five-year graded vesting at 20% a year you would be 40% vested: on $2,100 of match a year for two years, that is $1,680 kept out of $4,200 credited, with $2,520 returned to the plan. Your own contributions are always 100% yours.

Should I contribute more than the match threshold?

That is a personal decision this article can’t make. What the arithmetic shows is that the employer adds exactly $0 to every dollar above the cap — a 50%-to-6% plan pays $2,100 on a $70,000 salary whether you defer 6% or 20%. Reasons to go higher exist, but none of them involve the match.

Does the employer match count toward my annual contribution limit?

Not toward the elective deferral limit, which applies only to your own salary deferrals. It does count toward the separate, higher combined limit covering employee and employer contributions together. Both are set annually by the IRS and adjust for inflation, so look up the current year rather than trusting a figure you remember.

What if I’m paid biweekly and my plan doesn’t true up?

You risk under-collecting. Hit the annual deferral limit in October and a plan without a true-up stops matching for November and December, costing about two-twelfths of the annual match — roughly $350 on a $2,100 match. Spreading contributions evenly across all 26 pay periods avoids it entirely.

Where to check your own numbers

Three documents settle nearly every open question above. The summary plan description carries the exact match formula, the vesting schedule and whether a true-up exists. Your most recent statement shows the vested-versus-unvested split, which is often larger than people expect. The fund fact sheets in your plan menu carry the expense ratios that quietly rewrite every figure here.

This article is general information, not financial advice. See our disclaimer.

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