A 401(k) is an employer-sponsored retirement plan that lets employees save and invest money for retirement, often through automatic payroll deductions. Depending on the plan, you may contribute to a traditional 401(k), a Roth 401(k), or both.
Your contributions are then invested in options offered by the plan, such as mutual funds, index funds, bond funds, or target-date funds. Employers may also contribute matching money.
The tax treatment, contribution limits, investment choices, vesting rules, and withdrawal options can make a 401(k) one of the most important workplace benefits to understand.
What Is a 401(k)?
A 401(k) is a defined contribution retirement plan offered by an employer. It allows eligible employees to direct part of their pay into a retirement account, usually through payroll deductions.
The money in the account can be invested according to the options available in the employer’s plan. Over time, those investments may increase or decrease in value. The employee generally receives the account balance at retirement, rather than a predetermined retirement benefit.
One important distinction is that a 401(k) is the retirement plan or account structure, not an investment itself. A 401(k) does not automatically earn a fixed interest rate. The performance of the investments selected inside the plan determines how the account balance changes.
For example, an employee might contribute $500 from a paycheck to a 401(k). That $500 could then be allocated among several investment options offered by the plan. If the investments gain value, the account can grow. If they lose value, the account balance can decline.
How Does a 401(k) Work?
A typical 401(k) follows a relatively simple process:
- You choose a contribution amount: You generally elect to contribute a percentage or dollar amount from each paycheck.
- Your employer withholds the contribution: The money is deducted from your paycheck before being deposited into the plan.
- The contribution enters your 401(k): Depending on your election, it goes into a traditional or designated Roth account.
- You select investments: Your contribution is invested according to the choices available in your plan.
- The account changes with investment performance: Gains, losses, contributions, employer contributions, and fees can all affect the balance.
- You eventually take distributions: Withdrawals are generally subject to the tax rules and plan restrictions that apply to your type of account.
Your employer’s plan document controls many practical details, including eligibility, matching formulas, vesting, investment choices, loans, and distribution provisions. Federal tax rules establish important limits and requirements, but not every 401(k) works exactly the same way.
Traditional vs. Roth 401(k)
The biggest difference between traditional and Roth 401(k) contributions is when you pay income tax.
| Feature | Traditional 401(k) | Roth 401(k) |
|---|---|---|
| Contributions | Generally made before federal income tax | Made with after-tax income |
| Tax benefit today | Can reduce current taxable income | No current federal income-tax deduction |
| Investment growth | Generally tax-deferred | Can become tax-free if withdrawals are qualified |
| Qualified withdrawals | Generally taxable | Generally tax-free |
| Income limit to participate | No income limit for the Roth feature | No income limit for participating in a designated Roth account |
| Contribution limit | Shares the employee limit with Roth contributions | Shares the employee limit with traditional contributions |
The choice is not simply about which account is better. It is mainly a decision about whether you want the tax benefit now or potentially later.
With a traditional 401(k), contributions generally reduce the amount of your income subject to federal income tax for the year, although they generally remain subject to Social Security and Medicare taxes. You pay applicable income tax when you withdraw taxable money later.
With a Roth 401(k), contributions are included in your taxable income when made. Qualified withdrawals of Roth contributions and investment earnings can generally be tax-free.
For a Roth 401(k) distribution to be qualified, the applicable five-taxable-year requirement and an event such as reaching age 59½, death, or disability generally must be satisfied.
You may be able to contribute to both traditional and Roth portions of the same 401(k) during a year. However, your combined employee contributions cannot exceed the applicable annual employee contribution limit.
How Should You Think About the Traditional vs. Roth Choice?
A traditional 401(k) can be attractive when reducing taxable income today is particularly valuable. A Roth 401(k) can be attractive when you prefer to pay tax now in exchange for potentially tax-free qualified withdrawals later.
Your decision can depend on your current tax situation, expected future income, tax expectations, cash flow, and retirement goals. You do not need to assume that everyone in the same age group should make the same choice.
Some plans also allow employees to split contributions between traditional and Roth options. That can provide tax diversification, although the combined employee contributions remain subject to the annual limit.
How Much Can You Contribute to a 401(k) in 2026?
For 2026, the basic employee elective deferral limit for most 401(k) plans is $24,500. Employees who are age 50 or older by the end of the year can generally make an additional $8,000 catch-up contribution if the plan permits it.
A special higher catch-up limit applies in 2026 to eligible employees ages 60 through 63. For those employees, the higher catch-up limit is $11,250 instead of $8,000.
| 2026 401(k) limit | Amount |
|---|---|
| Basic employee contribution limit | $24,500 |
| Age 50+ catch-up | $8,000 |
| Age 60–63 higher catch-up | $11,250 |
| Total employee contribution for age 50+ | Generally $32,500 |
| Total employee contribution for ages 60–63 | Generally $35,750 |
| Overall annual additions limit, before catch-up contributions | $72,000 |
The $72,000 overall limit generally applies to employee elective deferrals, employer contributions, and certain other amounts. Catch-up contributions are handled separately under the applicable rules, so the maximum can be higher for eligible older employees.
Your plan can impose a lower employee contribution limit, and special rules can apply in certain circumstances. If you participate in multiple plans that share the same elective deferral limit, your contributions may need to be combined when determining whether you exceeded the limit.
How Does an Employer 401(k) Match Work?
An employer match is money your employer contributes to your 401(k) based on your own contributions, subject to the plan’s formula.
For example, suppose your employer matches 50% of the first 6% of your salary that you contribute. If you earn $60,000 and contribute 6%, you contribute $3,600 for the year. The employer could contribute another $1,800 under that matching formula.
The exact formula can be very different from one employer to another. Some plans may match a percentage of your contributions, while others may use different formulas or matching tiers.
The important point is to read your plan’s matching rules rather than assuming that every employer offers the same benefit.
Employer contributions are also different from your own contributions when it comes to vesting.
What Does 401(k) Vesting Mean?
Vesting determines when employer contributions become fully yours.
Your own 401(k) contributions are generally immediately 100% vested. You cannot lose your own contributions simply because you leave your job. Employer contributions, however, may be subject to a vesting schedule unless the plan requires immediate vesting.
For example, imagine you have $10,000 from your own contributions and $5,000 in employer contributions. If the employer’s contributions are only 60% vested when you leave, you generally keep your $10,000 plus the vested portion of the employer money, subject to the plan’s rules.
Your plan’s vesting schedule is therefore important when evaluating a job offer or deciding whether leaving an employer could affect your retirement savings.
How Is Money in a 401(k) Invested?
A 401(k) usually gives you a menu of investment options rather than allowing unlimited access to every investment available in the market.
Common choices can include:
- Target-date funds: Designed around an expected retirement year and generally become more conservative as that date approaches.
- Index funds: Designed to track a particular market index.
- Stock funds: Invest primarily in shares of companies.
- Bond funds: Invest primarily in bonds and other fixed-income securities.
- Other plan-specific funds: Some plans offer additional investment categories or managed options.
Investment choices vary by employer plan. Two people with 401(k)s can therefore have very different investment menus, fees, and plan features.
A larger number of investment choices is not automatically better. What matters is whether the available options fit your goals, risk tolerance, time horizon, and costs.
How Much Should You Contribute to a 401(k)?
There is no single contribution percentage that is appropriate for everyone.
A practical approach is to start by understanding your employer’s matching formula. If you are able to contribute enough to receive the full match, you may be able to capture an important workplace benefit.
After that, consider your overall financial situation. Your contribution decision may need to balance retirement savings with emergency savings, high-interest debt, housing costs, insurance, and other financial priorities.
You can also increase your contribution gradually. For example, increasing your contribution when you receive a raise can make saving more manageable because part of the additional income goes toward retirement instead of all of it going toward current spending.
The right amount depends on your income, age, retirement target, existing savings, expenses, and other financial resources.
When Can You Withdraw Money From a 401(k)?
A 401(k) is designed primarily for retirement, so access to the money is restricted by tax rules and the terms of your plan.
Generally, distributions made before age 59½ may be subject to ordinary income tax and an additional 10% federal tax unless an exception applies. The actual distribution rules depend on the plan and the type of money in the account.
There are exceptions to the additional 10% tax in certain circumstances. For example, a distribution from a qualified plan after separation from service can qualify for an exception when the separation occurs during or after the year the participant reaches age 55, subject to the applicable requirements.
This does not mean every withdrawal before 59½ is automatically tax-free. The income-tax treatment and the additional-tax rules are separate questions, and specific exceptions have their own requirements.
Your plan may also allow certain hardship distributions or other types of permitted withdrawals. Not every plan offers every option.
What Is a 401(k) Loan?
Some 401(k) plans allow participants to borrow from their accounts. However, loans are optional plan features, so not every 401(k) offers them.
A 401(k) loan is different from a normal withdrawal because the participant generally has to repay the borrowed amount under the plan’s terms.
Before taking a loan, consider the repayment requirements and what could happen if you leave your employer while the loan is outstanding. A loan can also reduce the amount of money remaining invested for retirement while the borrowed amount is outside the account.
What Are Required Minimum Distributions?
Required minimum distributions, or RMDs, are minimum amounts that generally must be withdrawn from traditional retirement accounts once applicable age requirements are reached.
For many retirement plan participants, the applicable RMD age is currently 73. A workplace plan may allow a participant who is still working to delay RMDs until retirement, although an exception generally applies to a person who owns more than 5% of the business sponsoring the plan. Plan terms also matter.
The rules are different for designated Roth accounts in a 401(k). Under current law, Roth 401(k) owners are not required to take lifetime RMDs from those designated Roth accounts.
Because RMD rules can affect taxes and retirement planning, older account holders should check the applicable rules and their specific plan rather than relying on a general age-based assumption.
What Happens to Your 401(k) When You Leave a Job?
Leaving an employer does not mean you have to cash out your 401(k).
Depending on the circumstances and the plans involved, common choices include:
| Option | Main consideration |
|---|---|
| Leave the money in the old 401(k) | You may retain access to the existing plan’s investments and features, subject to plan rules |
| Move it to a new employer’s plan | Can consolidate workplace retirement savings if the new plan accepts rollovers |
| Roll it into an IRA | May provide a broader range of investment choices, but fees and tax considerations should be reviewed |
| Take the money as cash | May create income taxes and, depending on the circumstances, an additional early-distribution tax |
The best choice depends on the fees, investment options, services, tax treatment, creditor considerations, and withdrawal features of the accounts involved.
Why Direct Rollovers Matter
A direct rollover generally transfers the money from one retirement plan directly to another eligible retirement account without the distribution being paid to you first.
If an eligible rollover distribution is paid to you instead, mandatory federal income-tax withholding generally applies to taxable distributions from an employer plan.
The standard withholding rate is generally 20%, and completing a full rollover may require you to replace the withheld amount with other funds.
For that reason, someone moving an old 401(k) should understand the difference between a direct rollover and receiving the money personally before completing the transaction.
401(k) vs. IRA
A 401(k) and an IRA are both retirement accounts, but they work differently.
| Feature | 401(k) | IRA |
|---|---|---|
| Established by | Employer | Individual |
| Employer match | May be available | No employer match |
| Investment choices | Determined by plan | Usually broader |
| Contribution limits | Generally higher | Generally lower |
| Traditional option | Yes | Yes |
| Roth option | May be available | Roth IRA available |
| Income limits | No income limit for Roth 401(k) participation | Roth IRA has income eligibility rules |
| Workplace payroll contributions | Yes | No, generally contributed separately |
Having a 401(k) does not automatically prevent you from having an IRA. However, the tax rules and eligibility requirements for deductible traditional IRA contributions and Roth IRA contributions are different from the rules for a workplace 401(k).
Is a 401(k) Worth Using?
For many employees, a 401(k) can be a valuable retirement-saving tool because it combines payroll saving, tax advantages, investment options, and potentially employer contributions.
Its value depends on the details of your particular plan. A plan with a useful employer match and reasonably priced investment options can offer significant benefits. At the same time, you should understand the plan’s fees, investment choices, vesting rules, and withdrawal restrictions before making decisions.
A sensible starting point is to review your plan documents and identify four things: your available contribution options, the employer match formula, the vesting schedule, and the investment choices and associated fees.
401(k) FAQs
Is a 401(k) a savings account?
Not exactly. A 401(k) is a retirement plan. The money inside it is generally invested in assets such as mutual funds, index funds, bond funds, or target-date funds. Its value can rise or fall based on those investments.
Does every employer offer a 401(k)?
No. A 401(k) is an employer-sponsored benefit, so not every employer offers one. Even when an employer offers a plan, eligibility requirements can vary.
Can I have both a traditional and Roth 401(k)?
If your employer’s plan offers a designated Roth feature, you may generally contribute to both traditional and Roth portions during the same year. Your combined employee contributions must stay within the applicable annual limit.
Can I have a 401(k) and an IRA?
Yes. You can generally have both. However, the tax deductibility of traditional IRA contributions and eligibility for Roth IRA contributions can depend on income and other factors.
Can I withdraw money from a 401(k) before age 59½?
You may be able to take a distribution if the plan permits it, but taxes and an additional 10% federal tax may apply unless an exception applies. Certain exceptions have specific requirements.
What happens to my 401(k) if I change jobs?
You generally have several options, including leaving the account in the old plan, moving it to a new employer’s plan if permitted, rolling it into an IRA, or taking a taxable distribution. The right option depends on your circumstances and the features of the accounts involved.
Do I lose my employer match if I leave my job?
You always keep your own vested contributions. Employer contributions may be subject to a vesting schedule, so you may not be entitled to all employer contributions if you leave before becoming fully vested.
Conclusion
A 401(k) is an employer-sponsored retirement plan that lets you save through payroll deductions and invest for the future.
The most important concepts to understand are how traditional and Roth contributions are taxed, how much you can contribute, how employer matching and vesting work, how your money is invested, and what happens when you need to withdraw or move the account.
For 2026, the basic employee contribution limit is $24,500, with additional catch-up opportunities for eligible older workers.
If you have access to a 401(k), start by reviewing your plan’s contribution options, employer match, vesting schedule, investment menu, and fees. Those details will help you make a more informed decision about how the plan fits into your overall retirement strategy.
