A 401(k) is a retirement savings account offered through your employer that lets you set aside a portion of each paycheck before (or after) taxes, invest that money, and let it grow until you retire. Many employers sweeten the deal by matching some of your contributions, which is essentially free money added to your account. The 2026 employee contribution limit is $24,500, with additional catch-up amounts available if you’re 50 or older.
How Contributions Come Out of Your Paycheck
When you enroll in a 401(k), you choose a percentage of your salary to contribute each pay period. That money is automatically deducted from your paycheck and deposited into your 401(k) account. You never see it in your checking account, which makes it one of the easiest ways to save consistently.
Most plans offer two flavors of contributions, and the difference comes down to when you pay taxes:
- Traditional 401(k): Your contributions come out before income taxes are calculated, which lowers your taxable income right now. If you earn $70,000 and contribute $10,000, you’re only taxed on $60,000 that year. The tradeoff is that you’ll owe income tax on every dollar you withdraw in retirement.
- Roth 401(k): Your contributions come out after taxes, so your paycheck shrinks more today. But qualified withdrawals in retirement are completely tax-free, including all the investment growth.
Many employers offer both options, and you can split contributions between them if you like. The combined total still can’t exceed the annual limit.
2026 Contribution Limits
For 2026, you can contribute up to $24,500 of your own salary to a 401(k). If you’re 50 or older, you can add an extra $8,000 in catch-up contributions, bringing your personal limit to $32,500. A special provision from the SECURE 2.0 Act gives an even higher catch-up limit to workers aged 60 through 63: $11,250 on top of the base $24,500, for a total of $35,750.
Employer matching contributions don’t count against your $24,500 limit. They fall under a separate overall cap that includes both your contributions and your employer’s.
How Employer Matching Works
Employer matching is one of the biggest advantages of a 401(k). Your company agrees to contribute additional money to your account based on how much you put in. The formula varies by employer, but common structures include:
- 100% match on the first 3%, plus 50% on the next 2%: If you earn $80,000 and contribute 5% ($4,000), your employer adds $3,200. That’s an instant 80% return on your contribution before any investment gains.
- 50% match on up to 6% of your salary: Contributing 6% of an $80,000 salary ($4,800) gets you $2,400 from your employer.
The key number to know is the threshold where your employer stops matching. Contributing at least enough to capture the full match is almost always worth it, because no other investment gives you that kind of guaranteed return.
Vesting Schedules
Your own contributions always belong to you, but employer matching dollars may come with a vesting schedule, a timeline that determines how much of the match you get to keep if you leave the company. The two most common structures are:
- Cliff vesting: You own 0% of matching contributions until you complete three years of service, at which point you’re 100% vested all at once.
- Graded vesting: You gradually earn ownership over six years. After two years you own 20%, after three years 40%, and so on until you hit 100% at six years.
If you leave your job before you’re fully vested, you forfeit the unvested portion. This is worth checking before you decide to switch employers, especially if you’re close to a vesting milestone.
What Your Money Is Invested In
A 401(k) isn’t a savings account sitting in cash. The money you contribute gets invested, and your plan will offer a menu of options to choose from. Most plans include some combination of:
- Mutual funds: Pooled investments that hold stocks, bonds, or both. These are the most common option in 401(k) plans.
- Target-date funds: A type of mutual fund that automatically shifts from stock-heavy to bond-heavy as you approach your expected retirement year. If you plan to retire around 2055, you’d pick a “2055 fund.” These are popular because they handle rebalancing for you.
- Stable value funds: Lower-risk options that invest in fixed-income securities and aim to protect your principal while paying modest interest. These are common for people close to retirement.
- Company stock: Some employers let you invest in shares of the company itself, though concentrating too much of your retirement in a single stock adds risk.
If you don’t actively choose your investments, many plans automatically place your money in a target-date fund based on your age.
Fees You’ll Pay
Every 401(k) charges fees, and they can quietly eat into your returns over decades. According to the Department of Labor, fees fall into three main categories:
- Plan administration fees: These cover recordkeeping, legal services, and account management. They may be charged as a flat dollar amount per account or as a percentage of your balance.
- Investment fees: Each fund in your plan charges an expense ratio, an annual percentage taken from the fund’s assets to cover management costs. An expense ratio of 0.50% on a $100,000 balance costs you $500 per year. Index funds often charge well under 0.10%, while actively managed funds can charge 1% or more.
- Sales charges (loads): Some mutual funds charge a fee when you buy shares (front-end load) or sell them (back-end load).
A difference of even half a percentage point in fees compounds significantly over a 30-year career. Your plan is required to provide a fee disclosure document at least once a year, and it’s worth reviewing to make sure you’re not paying more than you need to.
When You Can Withdraw the Money
The standard rule is straightforward: you can take penalty-free withdrawals starting at age 59½. Before that age, any withdrawal generally triggers a 10% early withdrawal penalty on top of regular income taxes (for traditional 401(k) money).
There are several exceptions to the 10% penalty:
- Rule of 55: If you leave your job during or after the year you turn 55, you can withdraw from that employer’s 401(k) without the penalty. Public safety employees get this benefit starting at age 50.
- Emergency personal expenses: You can take one penalty-free distribution per calendar year for emergency expenses, up to $1,000 or your vested balance above $1,000, whichever is less.
- Federally declared disasters: Qualifying individuals can withdraw up to $22,000 penalty-free if they suffer economic loss from a federally declared disaster.
- Domestic abuse victims: Victims of spousal or partner abuse can take a penalty-free distribution of up to $10,000 or 50% of their vested account, whichever is less.
Even when the 10% penalty is waived, traditional 401(k) withdrawals are still subject to income tax. Roth 401(k) withdrawals are tax-free as long as you’ve held the account for at least five years and are 59½ or older.
How Growth Compounds Over Time
The real power of a 401(k) comes from compounding. Your investment returns generate their own returns, and this snowball effect accelerates the longer your money stays invested. Someone who contributes $500 per month starting at age 25, earning an average 7% annual return, would have roughly $1.2 million by age 65. Waiting until 35 to start the same contributions cuts that figure nearly in half, to around $567,000. The extra decade of compounding accounts for the difference.
Tax-deferred growth amplifies this effect. In a traditional 401(k), the money that would have gone to taxes stays invested and compounds alongside everything else. In a Roth 401(k), your growth is never taxed at all. Either way, the 401(k) structure gives your investments more room to grow than a regular taxable brokerage account would.
What Happens When You Leave a Job
When you change employers, you have a few options for your existing 401(k) balance. You can leave it in your former employer’s plan if the balance is large enough (plans can force out balances under $5,000). You can roll it into your new employer’s 401(k) if they accept transfers. Or you can roll it into an individual retirement account (IRA), which often gives you a wider range of investment options and potentially lower fees.
The important thing is to do a direct rollover, where the money moves from one retirement account to another without passing through your hands. If you take a check instead, the plan is required to withhold 20% for taxes, and you’ll have 60 days to deposit the full amount (including the withheld portion from your own pocket) into another retirement account to avoid penalties.