The core difference: who your employer is

A 401(k) is offered by for-profit companies. A 403(b) is offered by nonprofits, public schools, colleges, and some government agencies. That single fact — your employer's legal structure — determines which plan you can join, how much you can contribute each year, and what happens to your money if you leave your job.

Both plans let you set aside pre-tax income for retirement, both charge taxes when you withdraw, and both penalize you if you take money out before age 59½. But the rules around how much you contribute, how you borrow from the account, and what happens to leftover money differ in ways that matter.

Key Takeaways

  • 401(k)s are for for-profit companies; 403(b)s are for nonprofits, public schools, colleges, and some government employers.
  • Both plans allow the same annual contribution limit ($23,500 in 2024 for people under 50), but 403(b)s have an additional catch-up rule for long-service employees that 401(k)s do not.
  • 401(k)s typically offer a wider range of investment choices; 403(b)s historically offered only annuities but now often include mutual funds.
  • Loans from a 401(k) are common and regulated; loans from a 403(b) depend on your plan's rules and are less standardized.
  • When you leave your job, you can roll both into an IRA, but the process and timing differ slightly between the two.

Contribution limits: where 403(b) offers more for long-term employees

For 2024, both plans allow you to contribute up to $23,500 per year if you are under age 50. If you are 50 or older, both allow an additional $7,500 catch-up contribution, bringing the total to $31,000.

A 403(b) has one extra rule: the 15-year service catch-up. If you have worked at your nonprofit or school for at least 15 years, you may be able to contribute an additional $3,500 per year (up to a lifetime limit of $15,000 extra). A 401(k) does not have this option. Your plan documents will state whether your employer allows this catch-up, so check with your benefits office to see if you may have access to.

Your employer may also match part of what you contribute — typically 3 to 6 percent of your salary. The match counts toward the annual limit, not in addition to it. Both 401(k) and 403(b) plans work the same way on this point.

Investment options: 401(k)s typically offer more choices

A 401(k) usually offers a menu of mutual funds, index funds, and sometimes company stock. You pick how to divide your contributions among these options, and you can change your allocation as often as your plan allows.

A 403(b) historically offered only annuities — insurance products that may provide a set payment in retirement. Many 403(b) plans still work this way. However, federal rules changed in 2006 to allow 403(b) plans to offer mutual funds alongside annuities. Whether your plan does depends on what your employer chose to set up. Ask your benefits office what investment options are available in your specific plan.

Annuities come with surrender charges if you withdraw early, and fees can be higher than mutual funds. 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 IRA after you leave your job.

Loans from your account: 401(k)s are more standardized

A 401(k) plan is required to allow loans if the plan document permits it. The rules are federal and consistent: you can borrow up to 50 percent of your vested balance (or $50,000, whichever is less), and you must repay it within five years through payroll deductions. If you leave your job, you typically have 60 to 90 days to repay the loan or it becomes a taxable withdrawal.

A 403(b) plan may or may not allow loans — it depends entirely on what your employer's plan document says. Some 403(b)s allow loans under the same rules as a 401(k). Others allow loans only under different terms. Still others do not allow loans at all. Contact your plan administrator to find out what your plan permits.

If you need to borrow from your retirement savings, confirm the loan rules in your specific plan before you assume you can do it. Treating a loan as a withdrawal by mistake can trigger taxes and penalties.

Employer oversight and plan administration

A 401(k) is heavily regulated by the Department of Labor and the IRS. Your employer must hire a plan administrator, follow strict rules about how money is invested and protected, and provide you with regular statements and disclosures. The employer is legally responsible for the plan's compliance.

A 403(b) is also regulated by the IRS, but the rules are somewhat less prescriptive. Historically, many 403(b) plans were administered by insurance companies with less employer oversight, which led to higher fees and less transparency. Federal rules tightened in 2009 to require more oversight, but 403(b) administration remains more varied than 401(k) administration. Some nonprofits and schools now hire third-party administrators similar to 401(k) plans; others still rely on insurance company administration.

This difference matters if you want to compare fees or investment performance. A 401(k) plan typically publishes a fee disclosure document; a 403(b) may not, and you may need to ask your plan administrator directly.

What happens when you leave your job

When you leave a job with a 401(k), you have four options: leave the money in the plan (if your balance is above a certain threshold, usually $5,000), roll it into an IRA, roll it into your new employer's plan, or cash it out. If you cash it out before age 59½, you owe income tax plus a 10 percent penalty on the full amount.

When you leave a job with a 403(b), the same four options exist, but the process can be slower. Some 403(b) plans require you to wait until the end of the plan year to take a distribution, or they may require you to work with an insurance company rather than a straightforward transfer. Check your plan documents or call your plan administrator to understand the timeline for your specific plan.

Rolling a 403(b) into an IRA is often the cleanest option if you want to consolidate accounts or access a wider range of investments. The rollover itself is not taxable — you are just moving money from one retirement account to another — but you must complete the transfer within 60 days or it becomes a taxable withdrawal.

Tax treatment: both are the same at withdrawal

Both 401(k) and 403(b) contributions reduce your taxable income in the year you make them. When you withdraw money in retirement, you pay income tax on the full amount at your ordinary tax rate. If you withdraw before age 59½, you also owe a 10 percent early withdrawal penalty, with limited exceptions (such as disability or substantial equal periodic payments).

The tax treatment is identical between the two plans. The difference is not in how you are taxed, but in how much you can contribute and what investment options you have along the way.

Frequently Asked Questions

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

Yes, if you work for both a for-profit company and a nonprofit or school. However, your combined contributions to both plans cannot exceed the annual limit ($23,500 in 2024 for people under 50). If you contribute $15,000 to a 401(k), you can contribute only $8,500 to a 403(b) that year. Check with both employers' benefits offices to coordinate.

Which plan is better for me?

That depends on your employer type — you do not choose between them. If you work for a for-profit company, you have a 401(k). If you work for a nonprofit, school, or college, you have a 403(b). Within your plan, compare the investment options, fees, and employer match to understand what you are working with.

Can I roll a 403(b) into a 401(k) at a new job?

Yes. When you start a new job with a for-profit employer that offers a 401(k), you can roll your old 403(b) balance into the new 401(k) plan. Your new employer's plan must accept rollovers — most do, but confirm before you leave your old job. The rollover is not taxable as long as you complete it within 60 days.

Do 403(b)s have lower fees than 401(k)s?

Not necessarily. Historically, 403(b)s had higher fees because they relied on insurance company administration. Today, it varies by plan. Some 403(b)s now use low-cost mutual fund platforms similar to 401(k)s, while others still charge higher annuity fees. Ask your plan administrator for a fee disclosure to compare.

What if my 403(b) plan only offers annuities?

You are still required to contribute if your employer offers the plan and you want to save for retirement. When you leave your job, you can roll the annuity balance into an IRA, which typically offers more investment choices. Annuities can be rolled over to IRAs, though you should understand any surrender charges before you do.