Everything You Need to Know About Your 401(k)

401(k) plans are an essential part of American life. They are a powerful tool: Achieving a secure, comfortable retirement depends primarily on how much money they can help you save. Yet many Americans don’t know enough about them to be able to protect themselves and ensure their future financial security.

Your 401(k) will likely become one of your biggest assets—so it’s important to familiarize yourself with how it works in order to protect your long-term financial security. Knowing how to evaluate investment strategies, how to judge whether your plan’s investments are generating good returns, and how to discern whether the costs associated with your plan are reasonable are all critical skills for a 401(k) plan holder preparing to retire and safeguard their financial security.

401(k) plans are governed by the Employee Retirement Income Security Act of 1974 (ERISA), a federal law that sets standards for how employers must manage these retirement accounts.

Building Long-Term Financial Security Through Your 401(k)

“401(k)” refers to a subsection of the Internal Revenue Code governing tax-advantaged, employer-sponsored retirement savings plans. “Employer-sponsored” means that 401(k) plans are available through companies; you cannot typically open one on your own unless you are self-employed. Basically, when you participate in a 401(k) plan through your company, you contribute to a trust established by your employer for the purpose of pooling untaxed money for you to use as “income” and long-term financial security in retirement.

You typically put money toward your 401(k) by electing to have a set amount deducted from each of your paychecks. This way, your earnings go directly to your account. Everything you put toward your 401(k) is a pre-tax contribution, which helps you save money.

401(k) Contribution Limits for 2025 and 2026

The Internal Revenue Service decides how much money plan participants are allowed to contribute to their plan accounts each year. In 2025, the contribution limit is $23,500. In 2026, that limit will be raised to $24,500. (You may not want to contribute the maximum amount each year. Like many 401(k) plan holders, you may simply not be able to do so. A general rule of thumb is that you should start saving as much as you can, as early as you can, to strengthen your long-term financial security. And the longer you wait to start, the more aggressive you should be about setting money aside for retirement.)

Note that the SECURE 2.0 Act, signed into law in 2022, introduced enhanced catch-up contribution provisions for participants aged 60–63, allowing them to contribute up to $11,250 in 2025. These provisions reflect ongoing legislative efforts to help Americans save more for retirement

Protecting Your Assets: Matching and Vesting Schedules

In addition to what you contribute, you may also receive an employer match, which can meaningfully improve your financial security in retirement. Employer match contributions tend to be capped. For example, your employer may match your 401(k) contributions dollar-for-dollar up to an amount equivalent to something like 5% of your salary. (This means that after they hit the cap they specified, any further contributions you decide to make will go unmatched.) Employer match contributions are also made pre-tax—again, helping you save more money.

Types of Vesting: Immediate, Cliff, and Graded

Your contributions to your 401(k) are always fully vested, meaning that the funds you put into your plan are yours from the moment they are deducted from your paycheck. If you leave your job, or if you change jobs, the funds you already contributed to your 401(k) will stay yours—they are protected.

Employer match contributions, by contrast, only become yours once they “vest.” Vesting occurs according to a set schedule. There are three dominant types of vesting schedules: immediate vesting, cliff vesting, and graded vesting.

• Immediate vesting means that employer match funds become yours as soon as they are deposited into your account, and they can never be taken back. (If you switch jobs, for example, that money can’t be pulled back by your former employer—it vested immediately, so it’s yours.)
• Cliff vesting might require you to work at the same company for several years before all of your employer’s match contributions vest at the same time, becoming yours after, say, three years.
• Graded vesting would provide for gradual year-over-year vesting, so that you have a right to more and more of your employer match every year that you remain in your position, until you become fully vested after several years. Being “fully vested” means that all the money in your 401(k) belongs to you.

Paying attention to your vesting schedule is crucial for protecting your financial security in retirement. If you are not fully vested yet, you may have less money available for your use than you think. Leaving your job before you are fully vested will forfeit unvested employer match contributions back to your employer—an important consideration especially if you are nearing retirement and seeking to secure your long-term financial health.

Retirement Planning: Withdrawal Rules and Penalties

Say that you are fully vested, and you’re ready to retire. When can you put your 401(k) to use? Typically, you must be older than 59½ to begin withdrawing money from your account without penalties. Importantly, though, if you are 55 or older and choose to leave your job for whatever reason, you can withdraw money without penalties as soon as you do so.

If you need to access your 401(k) funds before either of these conditions is met, you may incur an early withdrawal tax of 10% on all funds you remove from your account. This can negatively affect your long-term financial security in retirement. However, many plans offer qualified withdrawal exceptions, which is to say that there are certain circumstances under which you can remove money from your account early with no penalties. (These circumstances include birth of a child, disability, financial hardship, etc.)

That your withheld income and your employer match contributions accumulate in your plan tax-free is a huge advantage of 401(k) plans. It isn’t until you start withdrawing money from your account in retirement (or else in the case of qualified withdrawal) that you will have to pay income tax on that money.

The Fiduciary Duty: Protecting Your 401(k) Investments

In the meantime, you should focus on what investments will make the most of the untaxed money in your account and support your financial security over time.

The funds pooled in your 401(k) should not sit stagnant until you need to use them. Instead, your employer will appoint a fiduciary to put together a menu of investment options for you to choose from. Fiduciaries are obligated to provide you with a diverse array of low-cost, high-performing investment options to match your preferred level of risk and your specific retirement aims.

This obligation is codified in ERISA Section 404, which imposes the highest standard of care known in law, requiring fiduciaries to act solely in the interest of plan participants and beneficiaries, with the care, skill, prudence, and diligence of a knowledgeable professional. Violations of this duty can give rise to class action lawsuits on behalf of plan participants. Sanford Heisler Sharp McKnight has litigated landmark ERISA fiduciary breach cases against companies including UnitedHealth Group ($69 million settlement), General Electric ($61 million settlement), and Bloomberg ($70+ million pending).

Selecting Prudent 401(k) Investment Options

You direct how your funds are to be invested, so it’s in your best interest to make an informed decision that aligns with your long-term financial security goals. Several common investing options are as follows:

Money market funds

Funds in general are diverse investing portfolios, monitored by professional investors, that are composed of many types of investments. Money market funds typically present the lowest risk out of the several most common fund types. They invest in options such as Treasury bonds, certificates of deposit (CDs), etc. at $1 per share.

U.S. bond funds

Not risk-free, these options are tied to interest rates. When interest rates rise, the price of bond funds tends to fall.

Large-cap funds

These funds invest in large, successful U.S. companies, and are typically considered a stable, low-risk investment option.

Small-cap funds, which invest in smaller U.S. companies, as well as international-focused and emerging market funds, tend to have higher levels of risk than established American large-cap funds.

Target-date funds (TDFs)

These funds typically offer five-year vintages with specific goal retirement dates (e.g., goal retirement dates of 2040, 2045, 2050, etc.), the idea being that you would sign up for a plan whose level of investment risk is scheduled to decrease with time as your target retirement date approaches. These may be a good option if your desired level of risk is higher now—many years out from retirement—than you expect it to be, say, five years from your retirement.

Target-date funds are very common options for 401(k) plans, so much so that if you fail to select investment options from the menu of options your fiduciary provides, the entirety of your account may end up invested in a TDF by default (this is one possible plan policy that should be spelled out for you in the plan documents you are required to be given).

Risk Assessment for Retirement Readiness

When deciding how to invest your money, it’s important to be aware of how your choices may impact your financial security in retirement. More risk means that greater gains and greater losses are possible, and it makes your money more susceptible to market volatility. Deciding what level of risk you can tolerate should help inform what investment choices you want to make.

Benchmarking Fiduciary Performance

One way of checking an investment option’s suitability for your particular needs and aims is by seeing how it compares to the performance of its benchmarks. Benchmarks give you a glimpse into how the performance of your investment compares to the performance of the market.

401(k) fiduciaries are required to specify performance benchmarks—typically common, high-performing funds, such as the S&P 500—as comparators against which their own investment decisions should be judged. Typically, benchmarks will be specified in the Investment Policy Statement, which governs a fiduciary’s administration of the plan.

You may also want to conduct your own comparative research. If you are invested in large-cap funds, for example, you might want to compare their performance to the S&P 500 or Russell 1000 Index, both of which track leading large companies’ stock performance. If you are invested in a target-date fund, by contrast, the S&P Target Date Index may be a reasonable comparator for you to pay attention to. If these comparator funds greatly outperform the options where you have your money, you might consider making a change or raising a concern with your fiduciary about your 401(k)’s investment performance.

Holding Fiduciaries Accountable for Reasonable Fees

Your 401(k), through its investments, should make money for you over time. Any costs of administering the plan should be kept reasonable. The bulk of 401(k) operating costs are the fees charged by fiduciary investment managers who pick out investment options for you and who are supposed to continually monitor their performance. The costs they charge are passed onto you, and cut into your savings and long-term financial security in retirement. You have a right to consider the reasonableness of the fees they charge for their services.

Using Information to Ensure Your Financial Security

The most important part of being an engaged, proactive 401(k) plan holder is staying informed. Your 401(k) plan’s website, its annual disclosure statements, fund fact sheet, summary plan description, etc. are all invaluable resources you should use to learn more about your plan’s specific governing principles (including details about its vesting schedule, investment philosophy, and investment performance). When it comes to preparing for retirement and protecting your financial security, information is power. Arm yourself with the knowledge to take full advantage of all the benefits a wisely managed 401(k) plan can provide in the lead-up to your retirement. 

Frequently Asked Questions About 401(k) Financial Security