Failing to make a crucial retirement move can cost couples thousands over a lifetime. What you need to do now to grow your wealth

But this lack of coordination among couples “is common, costly, persistent over time and cannot be explained by inertia, auto-enrollment or simple heuristics,” according to the study’s authors.

By failing to optimize their retirement contributions, couples sacrifice an average of $14,000 in lifetime retirement wealth, with the top 10% of couples potentially losing up to about $40,000 (2).

Leaving employer-match money on the table

According to the Economic Innovation Group (EIG), roughly 55.5% of workers (or 44.5% of working Americans) lacked an employer-provided retirement plan in 2021. Access gaps are especially pronounced among lower-income workers: 79.4% of workers earning less than $42,200 did not have access to a plan.

Employers match contributions made by employees on a percentage basis, such as 25% or 50% — with some employers matching a full 100% — up to a set dollar amount or percentage of the employee’s salary.

Say, for example, your employer offers a 50% partial match up to 5% of your salary. If you make $100,000 per year, that means the maximum employer contribution would be $2,500. But you’d need to contribute the full 5%, or $5,000, to get the full employer match of $2,500.

Couples that each have an employer match are already at an advantage. Yet, when it comes to making financial decisions, some couples act more like roommates — managing their money individually rather than as a household, Taha Choukhmane, assistant professor of finance at MIT Sloan School of Management and co-author of the study, told CNBC (2).

“The absence of coordination can be a choice, but it’s a costly choice,” Choukhmane said.

But it’s not the only way Americans are leaving employer-match money on the table. One-quarter (25%) of employees “aren’t contributing enough to maximize their employer match,” potentially leaving thousands on the table, according to Empower research (3).

Other common mistakes include waiting to enroll (and missing months of matching), not understanding when matches are calculated (and missing out on matches) and not understanding “vesting” schedules (and leaving money behind when you switch jobs).

Another common mistake is not taking advantage of employer contribution matches to other accounts, such as a health savings account (HSA).

How to maximize your employer match

To maximize employer matching, contribute at least the percentage of your salary required to reach your employer’s match cap. If you’re part of a couple, make sure you’re coordinating your contributions.

“For instance, if one spouse has a dollar-for-dollar employer match up to a cap, and the other spouse has a 50 cents-on-the-dollar match, then the efficient allocation at the household level is to fully exploit the match offered to the first spouse before making any contribution to the second spouse’s account,” according to the study in American Economic Review (1).

By simply reallocating their existing contributions, couples could “increase their retirement wealth without changing their consumption” (1).

It’s not only couples who can benefit. Whether you’re an individual or a household, you’ll want to review employer-matching opportunities to avoid common mistakes.

For example, you should know when the match is calculated (say, per paycheck or annually). If you max out your 401(k) contributions early in the year but your employer matches contributions per pay period, then you could miss out on matches for the rest of the year. Check if your company offers a “true-up,” which means the employer will make up the difference if your contributions were uneven throughout the year.

You should also understand your company’s “vesting” schedule, which is a policy employers use to encourage employee retention. This means they provide full ownership of employer contributions only after you stay in your job for a set period of time — say, five years. If you leave early, you might forfeit the employer contributions (although your contributions are yours to keep). If you change jobs frequently, this should be a consideration.

For 2026, the 401(k) contribution limit for employees is $24,500, while the combined employee and employer contribution limit is $72,000. If you’re 50 or older, you can make an additional catch-up contribution of up to $8,000; if you’re between 60 and 63, you can make a higher catch-up contribution of up to $11,250 (4).

Go on a money date

Lack of communication can lead to other suboptimal financial decision-making, according to the study in American Economic Review, such as not refinancing a fixed-rate mortgage when it’s beneficial to do so, or co-holding low-interest liquid savings and high-interest credit card debt at the same time (1).