The core difference: who your employer is

A 401(k) is a retirement savings plan offered by for-profit companies. A 403(b) is a retirement savings plan offered by nonprofits, public schools, and some government agencies. That is the fundamental split. Both let you set aside money from your paycheck before taxes are taken out, and both let that money grow tax-deferred until you withdraw it in retirement. But the employer type determines which plan you get access to.

If you work at a bank, a tech company, a manufacturer, or any other business that operates for profit, your employer offers a 401(k). If you work at a hospital, a university, a public school district, or a nonprofit organization, your employer offers a 403(b). You do not choose between them — your employer's structure determines which one is available to you.

Key Takeaways

  • 401(k) plans are for employees of for-profit companies; 403(b) plans are for employees of nonprofits, public schools, and government agencies.
  • Both plans let you contribute pre-tax money and defer taxes on growth, but contribution limits, investment options, and employer match rules differ.
  • 403(b) plans historically had fewer regulatory protections and simpler rules, though that gap has narrowed in recent years.
  • Employer match (if offered) works the same way in both plans: the employer adds money based on what you contribute.
  • If you change jobs between a for-profit and a nonprofit, you will have a 401(k) at one and a 403(b) at the other, and you can roll money between them.

Contribution limits and how much you can save

Both plans have annual contribution limits set by the IRS, and those limits are usually the same. For 2024, you can contribute up to $23,500 of your own money to either plan (the limit changes yearly). If you are 50 or older, you can add an extra $7,500 as a catch-up contribution, bringing your total to $31,000.

The difference shows up in employer matching. A 401(k) employer match is capped at a percentage of your salary — typically 3 to 6 percent. A 403(b) employer match can sometimes be higher because nonprofits and schools operate under different rules. However, not all nonprofits and schools offer a match at all. Check your specific plan documents or ask your human resources department what match your employer provides.

Investment choices and who manages the money

A 401(k) typically offers a menu of mutual funds and index funds chosen by your employer. You pick from that menu. The employer usually hires a plan administrator (often a large financial company like Fidelity or Vanguard) to manage the overall plan and make sure it follows federal rules.

A 403(b) historically worked differently: you could often choose from multiple insurance companies or investment providers, each offering their own set of funds. This meant a 403(b) participant might have had more choice in some cases, but also less oversight and protection. In recent years, many 403(b) plans have moved toward the 401(k) model — a single administrator managing one menu of options. Ask your plan administrator or HR department which structure your 403(b) uses.

Employer protections and plan rules

401(k) plans are heavily regulated under federal law (ERISA — the Employee Retirement Income Security Act). That regulation means your employer must follow strict rules about how the plan is run, how your money is invested, and how fees are disclosed. There are legal protections built in.

403(b) plans have historically had lighter regulation, especially around fees and investment choices. That meant 403(b) participants sometimes paid higher fees or had fewer protections. However, the gap has narrowed. Many 403(b) plans now follow 401(k)-style rules, and the IRS has tightened requirements over time. Still, the level of protection can vary by plan. If you are in a 403(b), it is worth asking your HR department or plan administrator what protections and fee disclosures your specific plan provides.

Loans and early withdrawal rules

Both 401(k) and 403(b) plans allow you to borrow against your balance (usually up to 50 percent of what you have saved, with a maximum of $50,000). You repay the loan to yourself with interest. Both plans also charge a 10 percent penalty if you withdraw money before age 59½, plus you owe income tax on the withdrawal.

The rules around hardship withdrawals (money you can take out early for genuine financial need) are similar in both plans, though the specific hardships covered can vary slightly by plan. If you think you might need to access your money early, ask your plan administrator what your plan allows.

What happens when you change jobs

If you leave a job with a 401(k), you can roll that money into an IRA (Individual Retirement Account) or into a 401(k) at your new employer. If you leave a job with a 403(b), you can roll that money into an IRA or into a 403(b) at your new employer. You can also roll a 401(k) into a 403(b) or vice versa, though not all plans accept incoming rollovers — check with your new employer first.

The key rule: do not take the money out and deposit it yourself. That triggers taxes and penalties. Instead, ask your old plan administrator to do a direct rollover to your new plan or IRA. The money moves directly from one account to another, and you avoid the tax hit.

Roth options in both plans

Many 401(k) plans now offer a Roth option, which lets you contribute after-tax money (money you have already paid income tax on). That money grows tax-free, and you pay no tax on withdrawals in retirement. Some 403(b) plans offer Roth options too, though not all. If you want to use a Roth, ask your HR department whether your plan offers it.

You can split your contributions between the regular (pre-tax) version and the Roth version of your plan. For example, you might put $15,000 into the regular 401(k) and $8,500 into a Roth 401(k) in the same year, as long as your total does not exceed the annual limit.

Frequently Asked Questions

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

Only if you work two jobs — one at a for-profit company and one at a nonprofit or school. You can contribute to both plans in the same year, but your combined contributions to both cannot exceed the annual limit (currently $23,500). If you exceed the limit, you owe taxes and penalties on the overage.

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

Not necessarily. Historically, 403(b) plans sometimes had higher fees because they were less regulated. Today, fees vary widely in both types of plans. Ask your plan administrator for a fee disclosure document — it should list exactly what you are paying. Compare that to what similar plans charge.

If I roll my 403(b) into an IRA, can I roll it back into a 403(b) later?

Yes, but only if your new employer's 403(b) plan accepts incoming rollovers. Not all plans do. Before you roll money out of a 403(b), contact your new employer's HR department to confirm their plan accepts rollovers from outside sources.

What if my 403(b) plan does not offer an employer match?

Many nonprofits and schools do not offer a match. If yours does not, you still benefit from the tax deferral on your own contributions. You might also open an IRA (Roth or traditional) to save additional retirement money, though IRA contribution limits are lower than 403(b) limits.

Are 403(b) plans safer than 401(k) plans?

Both are protected by law, but 401(k) plans have stricter federal oversight. A 403(b) plan's safety depends on your specific plan and administrator. Ask your HR department what protections your plan provides and whether it follows ERISA rules.