Last updated: July 2026
This article is for informational and educational purposes only and is not investment, tax, or retirement advice. See our full Disclaimer for details.
Our Best ETFs for a Roth IRA and Best ETF Portfolio for Retirement guides both reference 401(k) accounts without fully explaining them. This article fills that gap — what a 401(k) actually is, how employer matching and vesting work, the difference between a traditional and Roth version, and what happens to the account when you change jobs.
The Basic Definition
A 401(k) is an employer-sponsored retirement savings plan, named after the section of the U.S. tax code that created it. Contributions are deducted directly from your paycheck and invested in a menu of options your employer’s plan offers — typically a selection of mutual funds, and increasingly ETFs, spanning different asset classes and risk levels. Unlike a Roth or traditional IRA, which you open independently through a brokerage, a 401(k) is tied specifically to your employer and is only accessible if your employer offers one.
Traditional vs. Roth 401(k): The Core Tax Difference
Many employers now offer both a traditional and a Roth version of their 401(k) plan, and understanding the difference mirrors the traditional-vs-Roth distinction covered in our Best ETFs for a Roth IRA guide, applied to an employer plan instead of an individually opened IRA.
Traditional 401(k) contributions are made with pre-tax dollars, directly reducing your taxable income in the year you contribute. The money then grows tax-deferred, and you pay ordinary income tax on withdrawals in retirement.
Roth 401(k) contributions are made with after-tax dollars — no upfront tax deduction — but qualified withdrawals in retirement, including all investment growth, are entirely tax-free, provided IRS requirements are met (generally including reaching age 59½ and having held the account for at least 5 years).
An important distinction from a Roth IRA: unlike a Roth IRA, which phases out at higher income levels as covered in our Best ETFs for a Roth IRA guide, a Roth 401(k) has no income limit — any employee whose plan offers the option can contribute, regardless of how much they earn.
Both traditional and Roth 401(k) contributions share the same overall annual contribution limit — you can split your contributions between the two, but the combined total across both cannot exceed the limit described below.
2026 Contribution Limits
Based on current IRS figures for 2026:
- Employee contribution limit: $24,500 (up from $23,500 in 2025), covering your own contributions across traditional and Roth 401(k) combined.
- Catch-up contribution (age 50-59, or 64 and older): an additional $8,000, bringing the total to $32,500.
- “Super” catch-up contribution (age 60-63): an enhanced $11,250 catch-up, in place of the standard $8,000, bringing the total to $35,750 — available only if your specific plan has adopted this option.
- Combined employee + employer contribution limit: $72,000 total (or 100% of your compensation, whichever is lower), covering your own contributions plus any employer match or other employer contributions.
A notable SECURE 2.0 Act rule: starting in 2026, employees who earned $150,000 or more in prior-year wages are generally required to direct their catch-up contributions specifically into the Roth (after-tax) portion of the plan, rather than being able to choose traditional pre-tax catch-up contributions — a mandatory routing rule that depends on your plan administrator having implemented the required system updates.
These figures are adjusted periodically by the IRS and can change; always confirm current limits directly with the IRS or your plan administrator.
Employer Matching: Often Called “Free Money”
Many employers offer to match a portion of your own contributions, effectively adding extra money to your account on top of what you personally contribute. Common matching formulas include:
- 100% match on the first 3% of salary — if you contribute 3% of your pay, your employer adds another 3%.
- 50% match on the first 6% of salary — if you contribute 6%, your employer adds an additional 3% (half of what you contributed).
- A fixed employer contribution — some employers contribute a set percentage of your pay regardless of whether or how much you personally contribute.
Employer matching contributions do not count against your $24,500 employee contribution limit — they’re a separate, additional amount, though they do count toward the overall $72,000 combined limit described above. This is a large part of why financial guidance so consistently recommends contributing at least enough to capture your full employer match before directing savings elsewhere — declining to do so effectively leaves part of your compensation unclaimed.
Vesting: Why the Match Isn’t Always Immediately “Yours”
This is a detail that surprises some employees, particularly those who change jobs relatively early in their tenure. While your own contributions are always 100% owned by you immediately, employer matching contributions are often subject to a vesting schedule — a period of continued employment required before you fully own that matched money.
Two common vesting structures:
Cliff vesting — You own 0% of the employer match until reaching a specific tenure milestone (commonly three years), at which point you become 100% vested all at once.
Graded vesting — Your ownership of the employer match increases gradually over time (for example, 20% per year over five years) rather than jumping from 0% to 100% at a single point.
If you leave your job before becoming fully vested, you forfeit the unvested portion of any employer match — the money is typically reallocated among remaining plan participants, not paid out to you. This is worth checking specifically if you’re considering leaving a job and are close to a vesting milestone, since the dollar amount at stake can be meaningful.
Investment Options Inside a 401(k)
Unlike an IRA, where you can typically choose from any ETF, stock, or mutual fund your brokerage offers, a 401(k) plan restricts you to a specific, employer-selected menu of investment options — often a mix of target-date funds, broad index funds, and a smaller number of actively managed choices. Some employers now include low-cost ETFs similar to those covered throughout this site, but plan menus vary considerably by employer, and you generally can’t add a fund to the menu yourself if it isn’t already offered. This is part of why many investors, once they leave a job, consider rolling old 401(k) balances into an IRA — doing so typically opens up a much broader range of investment choices than a former employer’s specific plan menu allowed.
What Happens to Your 401(k) When You Change Jobs
Leaving an employer doesn’t require you to do anything immediately with an existing 401(k) balance, but you generally have a few options:
Leave it with your former employer’s plan (if the plan and balance size allow this) — simplest in the short term, but means managing multiple retirement accounts across different employers over time.
Roll it into your new employer’s 401(k) (if the new plan accepts rollovers) — consolidates your retirement savings into a single active account.
Roll it into an IRA — generally opens up a much broader range of investment options than a typical 401(k) plan menu, a theme covered throughout this site’s fund-specific guides.
Cash it out — generally the option to avoid for most investors under most circumstances, since a cash-out before age 59½ typically triggers both ordinary income tax on the full amount and an additional 10% early withdrawal penalty, on top of permanently losing the account’s future tax-advantaged growth.
Rollovers between retirement accounts can generally be done without triggering taxes or penalties if executed correctly (a “direct rollover,” where funds move directly between institutions), but errors in the process can inadvertently trigger tax consequences — it’s worth confirming the correct rollover procedure with both the sending and receiving institutions before initiating a transfer.
Early Withdrawal Penalties
Withdrawing money from a 401(k) before age 59½ generally triggers both ordinary income tax on the withdrawn amount (for a traditional 401(k)) and an additional 10% early withdrawal penalty, with some exceptions — including certain hardship circumstances, specific medical expenses, and a few other IRS-defined situations. This penalty structure is a significant part of why 401(k) balances are generally treated as long-term, retirement-specific savings rather than a source of funds for near-term needs.
Required Minimum Distributions
Like a traditional IRA, traditional 401(k) accounts are subject to required minimum distributions (RMDs) beginning at a specific age, covered in more depth in our Best ETF Portfolio for Retirement guide. Roth 401(k) accounts, following a SECURE 2.0 Act change, are no longer subject to RMDs during the original account holder’s lifetime — a meaningful planning distinction from a traditional 401(k).
Frequently Asked Questions
Should I choose a traditional or Roth 401(k)? This depends on your current tax bracket relative to your expected tax bracket in retirement, among other factors — a traditional 401(k) provides an upfront tax deduction now, while a Roth 401(k) provides tax-free withdrawals later. This is a genuinely personal decision that a tax professional or financial advisor can help evaluate based on your specific situation; this article isn’t recommending one over the other.
Is employer matching worth prioritizing over other savings goals? Many financial professionals recommend contributing at least enough to capture the full employer match before directing savings elsewhere, since declining to do so means leaving part of your available compensation unclaimed. This is general guidance, not a personalized recommendation for your specific financial situation.
What happens to unvested employer match money if I leave my job? It’s generally forfeited and reallocated among the plan’s remaining participants — you don’t receive it, and it doesn’t follow you to a new employer. This is why checking your vesting schedule before leaving a job, if you’re near a vesting milestone, can be a meaningful financial consideration.
Can I contribute to both a 401(k) and an IRA in the same year? Generally yes — a 401(k) and an IRA (traditional or Roth) have separate contribution limits, meaning you can contribute to both up to their respective annual limits in the same year, subject to the Roth IRA income phase-out rules covered in our Best ETFs for a Roth IRA guide.
What if my employer doesn’t offer a 401(k) match? Some employers offer no match at all, or a smaller one than the common formulas described above. A 401(k) can still be worth contributing to even without a match, given its tax advantages and typically higher contribution limits than an IRA, though the specific investment menu and fees of your plan are worth evaluating compared to alternatives like an IRA.
Can I lose money in a 401(k)? Yes — a 401(k) is an investment account, not a guaranteed savings vehicle, and its value depends on the performance of whatever underlying funds you’ve selected from your plan’s menu. The tax advantages of a 401(k) don’t eliminate the underlying investment risk of the funds held within it.
This article is provided for general informational and educational purposes only and is not personalized investment, tax, or retirement advice. Contribution limits and rules referenced above reflect current IRS guidance for the 2026 tax year and are subject to change. Always verify current limits and rules directly with the IRS or your plan administrator, and consult a licensed financial advisor or tax professional before making retirement planning decisions. Read our full Disclaimer and Privacy Policy for more information.