By Thomas | financial enthusiast
My investing diary: day 7.
If your employer offers a 401(k) and you're not using it fully, you are almost certainly leaving free money on the table. Not a metaphor. Precise description of how employer matching works.
I didn't take this seriously until I did the actual math. First thought was "I'll figure it out later." Later cost me real money.
What a 401(k) Is
A retirement savings account offered through your employer. Named after the section of the US tax code that created it, it lets you contribute a portion of your paycheck before income tax is applied. The money grows tax-deferred inside the account — no tax on gains, dividends, or interest while it stays invested. Tax is owed only when you withdraw in retirement.
Key advantages over a standard brokerage account:
- Contributions reduce your taxable income today
- Growth is tax-deferred — no annual tax drag on gains
- Employers often match contributions — free money
- Contribution limits are significantly higher than an IRA
Key constraint: the money is meant for retirement. Withdrawing before age 59½ triggers income tax plus a 10% early withdrawal penalty. Treat it as untouchable until retirement.
The Employer Match: The Most Important Number in Your Benefits Package
A common structure: your employer matches 100% of contributions up to 3% of your salary, and 50% of contributions from 3–5%.
If you earn €60,000 and contribute 5% (€3,000), your employer adds:
- 100% of 3% (€1,800) + 50% of the next 2% (€600) = €2,400 free
That's an 80% instant return on the top portion of your contribution — before any investment growth. Nothing in stocks, crypto, or any other asset class guarantees an 80% return. The employer match is the only guaranteed high return in personal finance.
The minimum you should contribute: whatever captures the full employer match. Non-negotiable. Every paycheck you contribute less is a paycheck where you turned down free compensation. Damned.
Your employer's specific match formula is in your HR portal or benefits documentation. If you don't know what it is, find out today.
Contribution Limits (2024)
| Who | Limit |
|---|---|
| Employee contributions | $23,000 per year |
| Catch-up contribution (age 50+) | Additional $7,500 |
| Total including employer contributions | $69,000 |
Substantially higher than an IRA ($7,000). Once you've captured the full match and paid off high-interest debt, maxing the 401(k) is typically the next priority.
Traditional 401(k) vs Roth 401(k)
Many employers now offer both. Same logic as the IRA comparison:
Traditional 401(k): contributions pre-tax. Your taxable income is reduced now. Tax paid when you withdraw in retirement at your then-current rate.
Roth 401(k): contributions after-tax. No reduction today. All growth and withdrawals in retirement are tax-free. Unlike a Roth IRA, there are no income limits — anyone can contribute regardless of earnings.
For most people in their 20s and 30s, the Roth 401(k) is the better choice — though splitting between the two is a reasonable hedge if you genuinely can't decide.
One note: employer matching contributions are always pre-tax, even if you contribute to the Roth side. You'll owe tax on those matching contributions when you withdraw them. Annoying but important to know.
Vesting: When the Employer Match Actually Becomes Yours
Many employers apply a vesting schedule — the matching contributions aren't fully yours until you've worked there for a certain period.
Cliff vesting: you own 0% of the match until a set date (often 3 years), then 100% immediately. Leave before that date and you forfeit all matching contributions.
Graded vesting: gradually increasing ownership. Common schedule: 20% after year 1, 40% after year 2, 60% after year 3, 80% after year 4, 100% after year 5.
Your own contributions are always 100% yours immediately.
This is critical if you're considering changing jobs. Unvested employer contributions are real money. If your vesting cliff is six months away, that context belongs in your decision about when to leave.
What to Invest In: The Fund Selection Problem
Unlike a personal account at Vanguard or Fidelity, your 401(k) is limited to a menu of funds chosen by your employer. These menus vary widely in quality.
What to look for: the lowest-cost index funds on the menu. Look for "index" in the name. Check the expense ratio column. Most plans are required to disclose this.
Target funds:
- A total US stock market or S&P 500 index fund
- An international stock index fund (optional but good)
- A bond index fund
Target-date funds: most plans include these — named after your approximate retirement year (e.g., "Vanguard Target Retirement 2055 Fund"). They automatically hold a diversified mix and gradually shift toward bonds as the date approaches. Excellent default if you don't want to manage allocation manually. Slightly higher fees than holding the component index funds separately, but far better than holding cash or picking random actively managed funds.
What to avoid: funds with expense ratios above 0.5%. Actively managed funds with names like "Growth Opportunities" or "Dynamic Allocation." Anything that sounds exciting is usually expensive and underperforming.
If your plan only offers high-fee actively managed funds: contribute enough to get the full match, then prioritise a Roth IRA at Vanguard or Fidelity for the rest — where you have access to 0.03% index funds.
The Priority Order
Here's where each dollar should go, in order:
- 401(k) up to the full employer match — capture all free money first
- Pay off high-interest debt — credit cards above ~6–7%
- Roth IRA to the annual limit ($7,000 in 2024) — tax-free growth
- Max the 401(k) ($23,000 limit) — additional tax-advantaged growth
- Taxable brokerage account — no limits, no special tax advantages
Most people never get past step 3 or 4. That's completely fine. The list exists for when money is limited and you need to prioritize.
Rolling Over When You Change Jobs
When you leave an employer, your 401(k) options:
- Leave it — fine if the investment options are good and fees are low
- Roll over to your new employer's 401(k) — straightforward if the new plan accepts incoming rollovers
- Roll over to an IRA — widest fund selection, usually lowest fees. Use a direct rollover (trustee-to-trustee) to avoid triggering tax.
- Cash out — almost always the worst option. Income tax plus 10% penalty, plus losing all future compounding on the withdrawn amount.
For the rollover: contact your former plan administrator, request a direct rollover to your new IRA or 401(k). If money passes through your hands (indirect rollover), you have 60 days to deposit it before it's treated as a taxable distribution. Don't miss that window.
The Single Most Common Mistake
Not enrolling, or enrolling below the match threshold.
Many US companies auto-enroll at 3% — which often doesn't capture the full match. Employees who never review this setting contribute 3% indefinitely, leaving matching contributions uncollected. (haha, I did this my first year)
Log into your HR portal today. Find your current contribution rate. Find your employer's match formula. If you're below the match threshold, raise it immediately.
The paycheck impact is smaller than you expect: a €100 pre-tax contribution reduces take-home pay by roughly €78 in the 22% bracket, not €100.
The match is free. The tax deferral is valuable. The compounding over 30+ years is transformative. The 401(k) is the most accessible wealth-building tool most employees have, and the only thing standing between most people and using it fully is five minutes in an HR portal.
Do it now, not later. I wish someone had told me that more directly.
Any questions about 401(k)s or employer benefits you're still confused about?
