A beginner’s guide to your 401(k)

A 401(k) can be a powerful retirement savings tool, but your plan may be downgraded by high fees and poor investment options. We’ll explain everything you need to know about 401(k)s and other retirement savings vehicles you may want to consider if yours is subpar.

What is a 401(k)?

A 401(k) is an employer-provided retirement savings and investing plan that offers tax benefits. Build your 401(k) portfolio by picking from an investment menu that usually includes stocks, bonds and mutual funds.
To contribute to your 401(k), you set a percentage of your pay that you want to invest. Then, your employer automatically deducts that amount from each paycheck and invests it in your account.

Because your money flows from your check to your 401(k) before it’s taxed, it reduces your taxable income and can lower your tax bill each year. Some companies also match their employees’ contributions.

How is a 401(k) different from an IRA?

A 401(k) is similar to an individual retirement account (IRA). Anyone can open an IRA with a bank or brokerage, so you can opt for one if your company doesn’t offer a 401(k). But there are some key differences.

	Enrollment	2025 contribution limits	Tax advantages
401(k)	Enrollment period and eligibility is set by the employer Some automatically enroll eligible employees	$23,500 $31,000 if you’re 50 or older	Tax-deductible contributions Investment earnings grow tax-free in your account
IRA	You can enroll whenever you want	$7,000 $8,000 if you’re 50 or older	Tax-deductible contributions Investment earnings grow tax-free in your account

Because 401(k) plans vary widely because of employer choices, you may want to consider saving in an IRA in addition to or instead of a 401(k). You can compare retirement account options here.

How does a 401(k) grow?

Your 401(k) grows based on the performance of the assets it invests in. But it also benefits from compound interest. This means interest that your account earns one year is built upon by future earnings.
With simple interest, your interest only builds on the initial deposit. So if you deposited $10,000 and you get an annual interest rate of 9%, it grows by $900 every year. After 30 years, it’ll be $12,700.

Now let’s see how $10,000 would grow in a 401(k). Let’s say your annual interest or rate of return is still 9%. After 30 years, your 401(k) balance would grow to $147,305. And that’s assuming you don’t contribute anything beyond that $10,000 balance.

Who manages a 401(k)?

A 401(k) is managed by a plan sponsor. This sponsor can be your company or a third-party benefits firm. Plan sponsors hire asset-management companies that handle investing matters.

Can I lose money in a 401(k)?

As with any investment, your 401(k) can lose money. The assets your 401(k) invests in may not perform well some years, thereby cutting your earnings.

But think of a 401(k) as a long-term savings vehicle. Over time, markets recover from recessions and even crashes. In fact, the average stock market return for the last 50 years has been 10.9%.

Nonetheless, diversifying your portfolio is one of the best ways to protect your 401(k) from market downturns. This means investing in a variety of securities like stocks, bonds, exchange-traded funds (ETFs) and mutual funds.

Many 401(k) plans offer target-date funds (TDFs). These professionally managed, diversified portfolios automatically shift their investment mix to safer assets, such as bonds and money market funds, as you get closer to retirement age. While not the perfect investment, TDFs can be great tools for those who would rather hand off investment decisions to the pros.

What does 401(k) stand for?

The 401(k) plan is named after a subsection in the Internal Revenue Code. It allows employers to create retirement savings plans to which employees can contribute portions of their wages before taxes. It also permits earnings on these contributions to grow tax-free until they’re withdrawn from the account.

Section 401(k) was added to the code in 1978. But the first 401(k) plan didn’t launch until 1981 when benefits consultant Ted Benna interpreted the code to create one for a client.

401(k) types

There are two main types of 401(k) plans offered by employers.

	Eligibility	Contribution limits for 2025	Tax advantages
Traditional 401(k)	Determined by plan sponsor	$23,500 $31,000 if 50 or older	Tax-deductible contributions Earnings grow tax-free in the plan Withdrawals are taxed as part of ordinary income plus a 10% early withdrawal penalty if you’re under 59.5
Roth 401(k)	Determined by plan sponsor	$23,500 $31,000 if 50 or older	Contributions can be withdrawn any time regardless of age Earnings grow tax-free in the plan Withdrawals are tax-free if you’re 59.5 or older and the account has been open for at least five years

Note that the above limits apply to all types of 401(k) accounts, which fall under the umbrella of defined contribution (DC) plans. So if you have a traditional and a Roth 401(k), your contribution limit is $19,500 across both plans.

Also, the contribution limits listed above represent employee contributions, also known as elective deferrals. Some companies offer employer matches. The maximum contribution from you and your employer is $70,000.

However, the IRS states that contributions from all sources can’t exceed 100% of your compensation.

Our picks for 401(k) search and rollover services

Lifecycle of a 401(k)

To make the most out of your 401(k), it may be helpful to think of the lifecycle of the 401(k), from its inception through your retirement.

Opening a 401(k)

Some companies auto-enroll their employees in their 401(k) plan. So follow the instructions on your plan documents or ask your HR department for these. Otherwise, it’s a pretty straightforward process.

1. 1. Check with your HR department to see if you’re eligible. You may be eligible even if you’re working part time, thanks to the SECURE Act passed in 2019.
   2. If you’re eligible, ask your HR department about next steps. You may need to fill out some paperwork or set up an account online. Keep some information at hand.

1. Decide how much to contribute to your 401(k). Experts recommend 15% of your pay, but even starting with 3% and gradually increasing can help.
2. Choose investment options. Look out for fees like expense ratios if you’re choosing ETFs or mutual funds. These funds invest in a variety of assets like stocks and bonds, so they’re a good way to get diversified from the start.

Contributing to a 401(k)

Before you get your paycheck, your employer automatically deducts an amount of your choosing to direct to your 401(k) plan if you choose to contribute. It’s common practice to pick a dollar amount or a percentage of your pay.

How much of my salary can I contribute to my 401(k)?

Contribute the lesser of 100% of your salary or the applicable contribution limits set by the IRS each year. For 2025, the 401(k) contribution limits are $23,500 or $31,000 if you’re 50 or older.

How 401(k)s are taxed

The taxation of 401(k)s generally depends on the type of plan and the age at which you withdraw money.

Withdrawing from a 401(k)

Withdrawing from your 401(k) often comes with complex rules, and doing so without incurring heavy penalties requires meeting certain age requirements.

• Withdrawing from a traditional 401(k)
  • After 59.5: Withdrawals are considered part of your income, so these will be taxed at your federal tax-bracket rate. Some states will also tax your withdrawals. After age 73, you must take required minimum distributions (RMDs) based on the IRS Uniform Lifetime Table.
  • Before 59.5: Your withdrawals will be taxed as ordinary income plus a 10% early withdrawal penalty. The IRS also takes an automatic 20% early withdrawal withholding.
• Withdrawing from a Roth 401(k)
  • After 59.5: You can withdraw contributions and earnings tax-free. You must take required minimum distributions (RMDs) from a Roth 401(k) when you reach age 73.
  • Before 59.5: You can withdraw your contributions tax-free. But earnings will be taxed as ordinary income plus a 10% tax penalty.

The good news is that for some needs you can borrow money from your 401(k) and avoid penalties. Read the rules for 401(k) loans here.

Employer 401(k) contributions

Some companies offer employer matches. The rules for this vary across companies.

• Full match: Your company may match 100% of your contributions up to 3% of your annual salary. So let’s say your annual salary is $40,000. Your employer would match your contributions dollar-for-dollar up to $1,200 (3% of $40,000).
• Partial employer match: Your company may offer a 50% match on 401(k) contributions up to 6% of your annual salary. Let’s say your annual salary is $40,000. Your contributions eligible for matching would be $2,400. But because the company will match 50%, the most it can give is half of your contribution or $1,200.

4 alternatives to your employer’s 401(k)

If you find your 401(k) plan isn’t so hot, you have other options.

1. 1. Traditional IRA

A traditional IRA is essentially a traditional 401(k) that’s not provided by an employer.

1. 1. Roth IRA

This works similarly to a Roth 401(k), but nearly anyone can open a Roth IRA through a bank or brokerage.

Dive deeper: Roth IRA vs. Traditional IRA

1. 1. Health savings account

An HSA is a tax-advantaged savings and investing account designed to help you pay for medical expenses. But you can also use your HSA for retirement.

1. 1. Taxable brokerage account

This is your basic investing account.

Withdrawing without penalty

Withdraw from your 401(k) without penalty if you’re 59.5 or older. Early withdrawal penalties on some hardship withdrawals may be waived if your plan allows these.
The rules vary by plan. But you can usually waive the penalty if you need the money to cover the following.

• Medical expenses exceeding 7.5% of your adjusted gross income (AGI).
• Court-ordered payments to a divorced spouse, a child or a dependent.
• You lose your job at the age of 55 or later.
• You become disabled.

Triggering events for a 401(k) plan

Roll over a 401(k) when you experience a triggering event, also called a qualifying event. Your plan sponsor defines these events, but they’re usually the following.

• Job termination: You were either discharged from your company or changed jobs.
• Retirement age: You reached age 59.5.
• Death: Your family or beneficiaries can receive the funds in either a lump sum or in installments, which could stagger the taxes on the withdrawals.
• Disability: Your plan document would define disability.

4 options for triggering events

If a triggering event occurs in your life, you have several options.

1. 1. Roll the assets into an IRA.

1. 1. Leave the assets in the existing 401(k).

1. 1. Roll the assets into a new employer’s plan.

1. 1. Cash out.

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