401(k) Plan
Key Takeaways
- A 401(k) is an employer-sponsored retirement savings plan with tax advantages
- 2025 contribution limits are $23,500 (under 50) and $31,000 (50 and older)
- Many employers match a portion of employee contributions — essentially free money
- Traditional 401(k) contributions are pre-tax; Roth 401(k) contributions are after-tax
Definition
A 401(k) is an employer-sponsored tax-deferred retirement savings plan that allows employees to contribute a portion of their salary before taxes are withheld. Named after Section 401(k) of the Internal Revenue Code, the 401(k) is the most common retirement plan offered by private-sector employers in the United States.
Traditional 401(k) contributions reduce your current taxable income, and investments grow tax-deferred until withdrawal in retirement. Many 401(k) plans now also offer a Roth option, where contributions are made with after-tax dollars but withdrawals in retirement are tax-free, similar to a Roth IRA.
One of the most valuable features of 401(k) plans is employer matching. Many companies match employee contributions up to a certain percentage of salary — for example, matching 50% of contributions up to 6% of salary. This match is effectively free money and represents an immediate 50-100% return on the matched portion of contributions.
How It Works
Employees elect a percentage of their salary to contribute each paycheck, up to the annual limit of $23,500 in 2025 ($31,000 for those 50 and older with the catch-up contribution). Contributions are deducted from your paycheck before federal and state income taxes, immediately reducing your tax bill. However, Social Security and Medicare taxes still apply to the full salary.
The employer selects a plan administrator (such as Fidelity, Vanguard, or Schwab) that offers a menu of investment options, typically including index funds, target-date funds, bond funds, and company stock. Employees choose how to allocate their contributions among these options.
Vesting schedules determine when employer matching contributions become fully owned by the employee. Immediate vesting means the match is yours right away, while graded vesting may require 3-6 years before the full match is earned. Employee contributions are always 100% vested immediately.
Example
You earn $100,000 and contribute 10% ($10,000) to your traditional 401(k). Your employer matches 100% of the first 3% and 50% of the next 2% — a total match of 4% ($4,000). Combined, $14,000 goes into your account annually. The $10,000 contribution reduces your taxable income from $100,000 to $90,000, saving you $2,200 in taxes at the 22% rate. After 30 years at an 8% average return, these annual $14,000 contributions grow to approximately $1.6 million. The employer match alone contributed about $460,000 of that total — truly free money.
Why It Matters
The 401(k) is the primary retirement savings vehicle for most American workers. Higher contribution limits than IRAs, employer matching, automatic payroll deductions, and tax benefits make the 401(k) the foundation of retirement planning. Not contributing at least enough to capture the full employer match is leaving free money on the table.
Financial advisors nearly unanimously recommend maximizing your employer match as the first step in any investment plan. After capturing the full match, the decision to contribute more to the 401(k) versus an IRA or taxable account depends on the 401(k)'s investment options, fees, and your tax situation.
Advantages
- High contribution limits ($23,500 in 2025, $31,000 with catch-up)
- Employer matching provides free additional retirement savings
- Pre-tax contributions reduce current-year taxable income
- Automatic payroll deductions make saving effortless and consistent
Limitations
- Limited investment menu chosen by the employer, often with higher fees
- 10% early withdrawal penalty before age 59½ with limited exceptions
- Required minimum distributions begin at age 73
- Loans from 401(k)s can derail retirement savings if not repaid
Frequently Asked Questions
Related Terms
Browse more definitions in the financial terms glossary.