What Is a 403(b)?

A 403(b), sometimes called a tax-sheltered annuity (TSA) plan, is a retirement savings plan offered by certain employers in the public and nonprofit sectors: public school systems, colleges and universities, 501(c)(3) nonprofits, hospitals, and some churches. You agree to have part of your salary deferred into the plan, and that money is invested for retirement. The name comes from Section 403(b) of the Internal Revenue Code, just as a 401(k) is named for its own code section.

The core appeal is tax treatment. In a traditional 403(b) your contributions come out before income tax, which lowers your taxable income in the years you contribute, and the money grows without being taxed along the way; you pay ordinary income tax when you withdraw it in retirement. The plan is built specifically for employees who do not have access to a corporate 401(k), giving the public and nonprofit workforce a comparable way to save.

On the dimensions most people care about, a 403(b) and a 401(k) are nearly the same. They share the same annual employee contribution limit, the same age-50 catch-up, the same tax-deferred growth, the same option of a Roth version at many employers, and the same early-withdrawal rules before age 59 and a half. Employers can match contributions in either, though matching is less common in 403(b) plans, particularly in public schools.

The differences come down to who offers the plan and what is inside it. A 401(k) is for private, for-profit companies; a 403(b) is for public schools, nonprofits, and churches. A 403(b) carries a special catch-up for long-tenured employees that a 401(k) does not have. And historically a 403(b) menu has been more likely to be filled with annuity and insurance products rather than the low-cost index funds common in good 401(k) plans. Many 403(b) plans, especially government and public-school ones, are also exempt from ERISA, the federal law that sets oversight standards for most private retirement plans, which is part of why menu quality varies so much. For a side-by-side, see our 401(k) vs 403(b) guide.

For 2026, the employee elective deferral limit for a 403(b) is $24,500. If you are age 50 or older by the end of the year, you can add a catch-up contribution of $8,000, bringing your personal total to $32,500. Under the SECURE 2.0 rules, a higher catch-up applies at ages 60 to 63, set at $11,250 for 2026. The combined limit on all contributions, yours plus any employer money, is higher still. These numbers are adjusted by the IRS most years, so treat them as 2026 figures and verify with the IRS before you rely on them.

The 403(b) also has a catch-up that no 401(k) offers: the special 15-years-of-service catch-up. If you have 15 or more years of service with the same qualifying employer and have not contributed the maximum in earlier years, you may be able to add up to $3,000 a year on top of the normal limits, capped at $15,000 over your lifetime. The eligibility math is genuinely complicated and interacts with the age-50 catch-up, so confirm the specifics with your plan administrator and the IRS rather than assuming you qualify.

Many 403(b) plans let you choose between a traditional and a Roth version, and the difference is purely about when you pay tax. A traditional 403(b) takes contributions before tax: you reduce your taxable income today and pay ordinary income tax on withdrawals in retirement. A Roth 403(b) takes contributions after tax, so you get no deduction now, but qualified withdrawals later, including the growth, come out tax-free.

The usual framing is whether you expect your tax rate to be higher now or in retirement. Someone early in a career who expects to earn more later may favor the Roth; someone in a high-earning year who wants the deduction now may favor traditional. Some people split contributions between the two. The right answer depends on your personal tax situation, and Walnut is not a tax advisor, so this is not tax advice; a qualified tax professional can help you weigh it.

Here is the part of the 403(b) story that does not get told often enough. For decades, especially in K-12 public schools, 403(b) menus have been dominated by high-fee annuity and insurance products, frequently sold one-on-one to teachers by representatives in the break room. Variable annuities have historically charged average fees well above 2% a year, fixed annuities around 1%, while a broad low-cost index fund can cost under 0.1%. Those gaps compound brutally: over a few decades, a fee difference of one to two percentage points can erase tens of thousands of dollars of retirement savings.

Two structural features make this worse. Many annuity products carry surrender charges, penalties for moving your money out within a set number of years, so a poor choice is expensive to unwind. And because many 403(b) plans are exempt from ERISA oversight, there is often no fiduciary watching the menu the way there usually is in a private-sector 401(k). None of this means a 403(b) is a bad plan; the tax advantages are real and worth using. It means the wrapper and the fees inside it deserve as much attention as the decision to contribute.

A few practical checks separate a good 403(b) experience from a costly one. Look at the expense ratio of every option, the annual percentage the product charges, and favor low-cost index funds if your plan offers them. Ask whether a given product is an annuity or a mutual fund, and if it is an annuity, ask about surrender charges and how long they last. Watch for separate administrative or wrap fees layered on top of the fund cost. And find out whether your plan has a low-cost provider on its vendor list, since many districts offer one even when the annuity options are pushed harder.

People leaving a job or retiring often roll a 403(b) into an IRA at a low-cost provider precisely to escape a limited or expensive menu, which can widen the investment options dramatically. Whether that makes sense depends on your situation, including any valuable guarantees inside an existing annuity, so it is worth careful review. Walnut is informational and is not a financial or tax advisor; these are common patterns to be aware of, not instructions.

The plans are more alike than different, and the contribution limits are the same. The points that set a 403(b) apart are who offers it, the special 15-years-of-service catch-up, and the historical lean toward annuity products on the menu. Figures are 2026 values and change yearly; verify the current limits with the IRS. For the full comparison, see our 401(k) vs 403(b) guide.

The hardest part of a 403(b) is usually not contributing, it is understanding what you actually hold and what it costs. Annuity statements are dense, fees are buried, and the menu rarely tells you how an option compares to a plain index fund. Once money is rolled into an IRA at a brokerage, those questions get easier to answer with the right tool, because the holdings become readable line by line.

That is where Walnut fits. It connects your existing brokerage through SnapTrade and lets you ask, in plain language through Claude, ChatGPT, or a built-in assistant, how the investments inside a rolled-over 403(b) are doing, how concentrated or diversified they are, and how each position compares to the broad market. It is read-only until you choose to trade, and you approve anything that happens. Walnut is informational and is not a financial or tax advisor; it helps you see your own portfolio rather than telling you what to buy.

A 403(b) is the public and nonprofit sector's version of a 401(k): a tax-advantaged workplace plan for teachers, hospital staff, nonprofit employees, and church workers, with nearly identical tax rules and a 2026 employee limit of $24,500 (verify with the IRS). Its distinctive features are the special 15-years-of-service catch-up and, less happily, a long history of high-fee annuities crowding the menu. The tax benefits are worth using; the fees are worth scrutinizing.

Decide between traditional and Roth based on your tax picture, contribute what you can, and read the fine print on any annuity before you choose it. If you later roll a 403(b) into an IRA, you can study the new holdings as an individual stock, an ETF, or a theme you want exposure to. Limits and rules change every year; treat the specifics here as a 2026 starting point and confirm with the IRS and a qualified tax professional before deciding.