A 401(k) is one of the most powerful retirement tools available to US workers — automatic payroll contributions, potential employer matching, tax advantages, and high contribution limits compared to an IRA. But to get the most out of it, you need to understand how the match works, how much you're allowed to contribute, which 'flavor' of 401(k) makes sense for you, and what happens to the money if you leave your job.
Employer matching: free money, with conditions
Many employers match a portion of your contributions — a common formula is '100% match on the first 3% of salary' or '50% match on the first 6%.' If you earn $80,000 and your employer offers a 100% match up to 3%, contributing at least 3% ($2,400/year) gets you another $2,400/year from your employer — an instant, guaranteed 100% return that no investment can reliably match.
The single most common retirement-planning mistake is contributing less than the amount needed to capture the full match. Even if you can't afford to contribute much else, contributing enough to get the full match should usually be the first priority — ahead of almost everything except high-interest debt.
2026 contribution limits
For 2026, the employee contribution limit for 401(k) plans is $24,000 for workers under 50. This is the maximum you can defer from your own paycheck — it does not include employer matching contributions, which have their own separate combined limit.
Workers age 50 and older can make additional 'catch-up' contributions on top of the standard limit, allowing them to set aside significantly more as retirement approaches. Under SECURE 2.0 rules, workers aged 60–63 may be eligible for an even higher 'super catch-up' amount. If your plan allows it and your budget permits, these catch-up contributions are a powerful way to accelerate savings in your final working years.
Use the 401(k) Calculator to see exactly how your contribution rate compares to these limits and whether you're on track to max out.
Traditional vs. Roth 401(k)
A traditional 401(k) reduces your taxable income today — contributions come out of your paycheck before taxes — but withdrawals in retirement are taxed as ordinary income. A Roth 401(k) is funded with after-tax dollars, so there's no tax break now, but qualified withdrawals in retirement, including all growth, are completely tax-free. If you expect your tax rate in retirement to be similar to or higher than today (common for younger workers early in their careers, or anyone expecting tax rates to rise), Roth contributions can be more valuable. Many plans allow you to split contributions between both types for flexibility.
Vesting schedules
Your own contributions are always 100% yours immediately. Employer matching contributions, however, are often subject to a 'vesting schedule' — a timeline you must work to fully own that money. Common schedules include 'cliff vesting' (0% ownership until a certain number of years, then 100% all at once) and 'graded vesting' (ownership increases gradually, e.g., 20% per year over five years). If you leave a job before you're fully vested, you forfeit the unvested portion of employer contributions — so it's worth checking your plan's vesting schedule before deciding when to change jobs.
What happens when you change jobs
When you leave an employer, you generally have a few options for your 401(k) balance: leave it with your former employer's plan (if allowed), roll it over into your new employer's 401(k), roll it over into an IRA, or — generally not recommended — cash it out, which triggers income tax plus a 10% early withdrawal penalty if you're under 59½.
A direct rollover (where funds move trustee-to-trustee, never passing through your hands) avoids taxes and penalties and is usually the simplest option. Rolling into an IRA can also give you access to a wider range of investment choices than many employer plans offer.
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Frequently Asked Questions
What is the 401(k) contribution limit for 2026?+
The employee contribution limit is $24,000 for workers under 50. Workers 50 and older can make additional catch-up contributions on top of this limit, and those aged 60–63 may qualify for an even higher 'super catch-up' amount under SECURE 2.0.
Should I prioritize my 401(k) match over an IRA?+
Generally yes — contribute enough to your 401(k) to capture the full employer match first, since that's an immediate guaranteed return. After that, consider whether an IRA (often with lower fees and more investment choices) or additional 401(k) contributions make more sense for you.
Can I have both a traditional and a Roth 401(k)?+
Yes, many employer plans allow you to split your contributions between traditional (pre-tax) and Roth (after-tax) within the same overall contribution limit. This gives you tax diversification — some money taxed now, some taxed later.
What happens to my 401(k) if I'm laid off?+
Your vested balance remains yours. You can typically leave it in the old plan, roll it into your new employer's 401(k), or roll it into an IRA without triggering taxes or penalties, as long as it's a direct rollover.