Understanding 401(k) Matching, True-Ups, and How to Set Your Contributions Correctly

By: Alex Simons

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A 401(k) is one of the most powerful tools available for building long-term wealth— but many people don’t fully understand how employer matching works or how small contribution mistakes can leave money on the table. One of the most overlooked details? The employer match and the “true-up” provision.

Let’s break it down.

What Is a 401(k) Employer Match?

An employer match is exactly what it sounds like: your company contributes money to your retirement plan based on how much you contribute.

Common matching formulas include:

• 50% match up to 6% of pay

• 100% match up to 4% of pay

• Tiered matches (e.g., 100% on the first 3%, then 50% on the next 2%)

This is essentially free compensation—but only if your contributions are structured correctly.

How Most Employers Calculate the Match

Here’s the part many people miss: Most employers calculate the match per pay period, not annually.

That means:

• Each paycheck has a maximum match available

• If you don’t contribute enough in a given paycheck, that “missed” match may be gone forever

This is where contribution timing matters.

What Is a 401(k) “True-Up”?

A true-up is an annual reconciliation done by some employers to make sure you receive the full match you were entitled to based on your total annual compensation and contributions—even if you missed match opportunities during the year.

In simple terms:

• With a true-up: Your employer checks at year-end and “tops you off” if you under-received matching dollars

• Without a true-up: Missed match opportunities are gone

Not all plans offer true-ups, and many employees don’t know whether theirs does.

Why This Matters More Than You Think

Let’s look at a common mistake: You receive a bonus or raise and decide to frontload your 401(k), hitting the IRS contribution limit early in the year.

• If your employer does not offer a true-up: You may stop contributing mid-year You could miss matching contributions for every remaining paycheck

• If your employer does offer a true-up: You’ll typically be made whole at year-end

Over a career, missing employer match—even by a small amount each year—can cost tens or hundreds of thousands of dollars in lost growth.

What to Check in Your 401(k) Plan Documents

To avoid leaving money on the table, confirm these details in your Summary Plan Description (SPD) or with HR:

1. Does the plan offer a true-up?

2. Is the match calculated per paycheck or annually?

3. Is the match capped each pay period?

4. Does the match apply to bonuses or only base pay?

5. Is there a vesting schedule on employer contributions?

These details directly affect how you should structure your contributions.

Best Practices for Setting Up Your Contributions

Here are dynamic guidelines for most people to consider:

• If there is no true-up: Spread contributions evenly across all paychecks so you capture the match every period.

• If there is a true-up: You may have more flexibility to front-load contributions —but still confirm timing and payout rules.

• If you receive bonuses: Check whether bonuses are eligible for matching and whether your contribution percentage applies to them.

• If your income fluctuates: Review contributions mid-year to ensure you’re on track for both the IRS limit and full employer match.

The Bottom Line

Your 401(k) match is one of the highest-return benefits your employer offers—but it’s not automatic. Contribution timing, plan mechanics, and true-up provisions all matter.

• A well-set contribution strategy ensures:

• You maximize employer dollars You avoid accidental match losses

• Your retirement savings work as efficiently as possible

If you’re unsure how your plan works or want help managing your contributions, it’s worth reviewing your strategy with a financial professional. Small adjustments today can lead to significantly better outcomes over time.