What Is a 401(k)?
A 401(k) is an employer-sponsored retirement savings plan that lets you contribute pre-tax salary into an investment account. Money grows tax-deferred until withdrawal in retirement. Many employers match contributions — essentially free money.
How a 401(k) Works
With a traditional 401(k), contributions come out of your paycheck before income taxes are calculated, reducing your taxable income today. The money grows tax-deferred — you pay no taxes on gains, dividends, or interest until you withdraw in retirement. Some employers also offer a Roth 401(k) option, where contributions are made after tax but withdrawals in retirement are completely tax-free.
Many employers offer a matching contribution — for example, matching 50% of your contributions up to 6% of your salary. This is essentially free money and provides an immediate 50% return on your investment. Not contributing enough to get the full employer match is one of the most common financial mistakes working Americans make.
Why a 401(k) Matters for Your Financial Goals
The 401(k) is one of the most powerful wealth-building tools available because it combines tax advantages, employer matching, and the power of compound interest over decades. Contributing consistently from the start of your career — even small amounts — can result in substantial retirement savings due to compounding.
The annual contribution limit for employees is $23,500 in 2025, with an additional $7,500 catch-up contribution allowed for those aged 50 and over. At minimum, financial educators recommend contributing enough to capture your employer's full match before directing savings elsewhere.
Key Takeaway
If your employer offers a 401(k) match, contribute at least enough to get the full match. Not doing so is leaving free money on the table.
Related Terms
IRA
An IRA (Individual Retirement Account) is a tax-advantaged account for retirement savings. A Traditional IRA offers tax-deductible contributions with taxes paid at withdrawal. A Roth IRA uses after-tax contributions but offers completely tax-free withdrawals in retirement.
Roth IRA
A Roth IRA is an individual retirement account offering tax-free growth and tax-free qualified withdrawals. You contribute after-tax dollars (no deduction now) but pay zero taxes on withdrawals in retirement — including all investment gains.
Retirement Planning
Retirement planning is the process of determining how much money you'll need in retirement and developing a strategy to accumulate those funds — through accounts like 401(k)s and IRAs, investment strategies, and consistent saving over time.
Compound Interest
Compound interest is interest calculated on both your initial principal and the accumulated interest from previous periods. In simple terms, it's earning interest on your interest — and it's one of the most powerful forces in personal finance.