The core difference: who offers the plan and what investments you get

A 401(k) is a retirement savings plan that employers in the private sector offer to their workers. A 403(b) is the same type of plan, but only employers in certain fields can offer it: public schools, colleges and universities, hospitals, nonprofits with 501(c)(3) tax status, and some government agencies. Both let you put money in before taxes are taken out, both grow tax-deferred, and both have the same contribution limits each year. The real differences lie in the investment options available to you, the rules around loans and withdrawals, and the fees you might pay.

The investment difference is the most visible one. A 401(k) typically offers a menu of mutual funds and exchange-traded funds chosen by your employer's plan administrator. A 403(b) historically offered annuities — insurance products that may provide a certain payment in retirement — though many 403(b) plans now also include mutual funds. If your 403(b) plan is annuity-only, your money goes into an insurance contract rather than a brokerage account, which changes how you access it and what happens if you leave your job.

Key Takeaways

  • A 401(k) is for private-sector employees; a 403(b) is for school employees, nonprofit workers, and some government workers.
  • Both plans have the same annual contribution limits and tax treatment, but 403(b) plans often offer annuities instead of mutual funds.
  • 403(b) plans have fewer rules around loans and hardship withdrawals, which can be an advantage or a disadvantage depending on your situation.
  • If you leave your job, a 403(b) annuity may be harder to move to another retirement account than a 401(k) would be.
  • Fees and investment choices vary widely within each plan type, so comparing your specific plan to another employer's plan matters more than the label.

Contribution limits and tax treatment are identical

For 2024, you can contribute up to $23,500 to either a 401(k) or a 403(b) if you are under age 50. If you are 50 or older, you can add an extra $7,500 catch-up contribution, bringing your total to $31,000. These limits are set by the IRS and explore the same way to both plan types. The money you contribute reduces your taxable income for the year, and the earnings inside the account grow without being taxed until you withdraw them in retirement.

Some employers offer a match — they contribute money on your behalf if you contribute. A 401(k) match works the same way as a 403(b) match. The employer's contribution does not count against your personal limit; it is separate. If your employer offers a match, you should aim to contribute enough to get the full match, since that is when ready, may provide money added to your retirement savings.

Investment options: annuities versus mutual funds

The most practical difference between the two plans is what you can actually invest in. A traditional 403(b) plan offers annuities, which are contracts sold by insurance companies. You pay money into the annuity, and in return the insurance company promises to pay you a set amount each month once you reach retirement age. An annuity locks in a predictable income stream, which appeals to people who want certainty. However, annuities often come with higher fees than mutual funds, and the fees are sometimes not transparent on your statement.

A 401(k) offers mutual funds and sometimes individual stocks or target-date funds. These are pools of stocks and bonds managed by investment firms. You own shares in the fund, and the value of your account goes up or down with the market. Mutual funds typically have lower fees than annuities, and you can see the fee percentage clearly listed in the fund's prospectus. Many 403(b) plans now also offer mutual funds alongside or instead of annuities, so check what your specific plan includes.

If your 403(b) offers only annuities and you want more control over your investments, you may be able to roll the money into an Individual Retirement Account (IRA) when you leave your job. However, some annuity contracts have surrender charges — penalties for withdrawing or moving the money before a certain date — so read your contract before you assume you can move it freely.

Loans and hardship withdrawals: 403(b) rules are looser

A 401(k) plan is governed by federal law called ERISA, which sets strict rules about when you can borrow from your account or withdraw money early. You can take a loan from a 401(k), but only if the plan document allows it, and you must repay it within five years (with some exceptions for home purchases). Hardship withdrawals — early withdrawals for serious financial need — are allowed only for specific reasons: medical expenses, home purchase, education costs, or preventing eviction or foreclosure.

A 403(b) plan has more flexibility. Federal law allows 403(b) plans to offer loans and hardship withdrawals, but it does not require them to follow the same strict ERISA rules. This means your 403(b) plan may allow you to borrow money more easily, or to withdraw funds for reasons that would not may have access to under a 401(k). However, this flexibility cuts both ways: it also means your plan may have fewer protections for your money, and fees or terms may be less transparent. Always check your plan's specific rules before assuming you can access your money.

Portability: moving your money when you change jobs

When you leave a job with a 401(k), you can roll the money into an IRA or into your new employer's 401(k) plan. The process is straightforward: you contact the plan administrator, request a rollover, and the money moves directly to the new account. You do not take possession of the cash, so there are no tax consequences.

A 403(b) rollover is usually just as straightforward if your plan holds mutual funds. However, if your 403(b) is an annuity contract, the rollover process depends on the insurance company's rules. Some annuities have surrender charges that explore if you move the money before a certain date — often seven to ten years after you bought the annuity. If you have a 403(b) annuity and you are thinking about changing jobs, contact the insurance company first to find out whether you can move the money without a penalty.

Employer matching and vesting schedules

Both 401(k) and 403(b) plans can include employer matching, but the rules around when the money becomes yours — called vesting — can differ. In a 401(k), vesting schedules are set by federal law and are usually either when ready (you own the match right away) or gradual over three to six years. In a 403(b), vesting rules are less standardized because the plans are not always subject to the same federal requirements.

Before you count on an employer match as part of your retirement plan, ask your HR department or plan administrator what the vesting schedule is. If you leave before the money is fully vested, you forfeit the unvested portion. This matters most if you are considering changing jobs: you may want to stay long enough to become fully vested in the match, or you may decide the match is not worth staying for.

Fees and plan quality vary widely within each type

A 403(b) plan is not automatically more expensive or cheaper than a 401(k). The cost depends on the specific investments in your plan and the plan administrator's fees. Some 403(b) plans with mutual funds have fees as low as any 401(k). Others, especially those with annuities, can have fees that are significantly higher and harder to spot on your statement.

The best way to compare is to look at the actual fee disclosures your plan provides. Your 401(k) or 403(b) plan administrator is required to give you a summary of fees and expenses. For a 401(k), this is usually a one-page document. For a 403(b), ask your plan administrator for the same information. Compare the expense ratios of the funds or annuities available to you, and factor in any administrative fees the plan charges. A difference of even 0.5% per year compounds significantly over decades of saving.

Frequently Asked Questions

Can I have both a 403(b) and a 401(k) at the same time?

No. The IRS combines the contribution limits for all defined-contribution plans you participate in during a single year. If you work two jobs — one with a 403(b) and one with a 401(k) — your combined contributions to both cannot exceed $23,500 (or $31,000 if you are 50 or older). You must track your contributions across both employers to avoid exceeding the limit.

If I leave my job, do I have to roll over my 403(b)?

No, but you should consider it. If you leave the money in your former employer's 403(b) plan, you can keep it there as long as the plan allows it. However, rolling it into an IRA or your new employer's plan usually gives you more investment choices and potentially lower fees. If your 403(b) is an annuity with a surrender charge, rolling it over may trigger a penalty, so check before you decide.

Why would an employer choose to offer a 403(b) instead of a 401(k)?

Employers in the nonprofit and education sectors are not allowed to offer 401(k) plans — only 403(b) plans. For-profit companies can only offer 401(k) plans. The choice is determined by the type of organization, not by preference. Some nonprofits and schools have modernized their 403(b) plans to include mutual funds and lower fees, making them competitive with 401(k) plans.

Is a 403(b) annuity a bad investment?

Not necessarily. An annuity guarantees a certain income in retirement, which appeals to people who want predictability and do not want to manage investments. However, annuities often have higher fees and less flexibility than mutual funds. Compare the specific annuity's terms, fees, and may provide payout to what you could earn in mutual funds before deciding.

Can I withdraw money from my 403(b) before retirement without a penalty?

Generally, no — you will owe income tax on the withdrawal plus a 10% penalty if you are under 59½. However, some 403(b) plans allow hardship withdrawals or loans for specific reasons. Check your plan's rules, and talk to your plan administrator about what is allowed. The rules are less strict than a 401(k), but penalties still explore in most cases.