How a 403(b) builds retirement savings
A 403(b) works on a simple but powerful idea: money you set aside today goes in before income tax, lowering your taxable income now, and then grows untouched by tax until you withdraw it in retirement. That deferral lets the full balance compound year after year instead of being trimmed by annual tax bills. Many plans also offer a Roth 403(b) variant, where you contribute after-tax dollars in exchange for tax-free qualified withdrawals later — a choice worth weighing against your expected tax rate in retirement, which ourRoth vs traditional calculatorcan help you compare. Because a 403(b) and a401(k)share nearly identical mechanics, the same saving habits apply to both.
How the projection works
Monthly contribution = employee amount + employer match
Each month: balance grows at the assumed return, then contributions are added
The calculator compounds your combined monthly contributions at the assumed annual return, month by month, until retirement. It then breaks the final balance into two parts — the total you and your employer actually contributed, and the investment growth earned on top — so you can see how much of your nest egg comes from saving versus compounding.
Worked example
Take a hospital employee earning $60,000 a year with $50,000 already saved, contributing 10% of salary with a 5% employer match, earning 7% a year for 25 years until retirement:
| Step | Amount |
|---|---|
| Current 403(b) balance | $50,000 |
| + Your contributions over 25 years10% of a $60,000 salary — $500 a month | $150,000 |
| + Employer matcha 5% match adds $250 a month of free money | $75,000 |
| + Investment growthcompounding monthly at 7% a year on the whole balance | $618,825 |
| = Balance at retirement$275,000 of money put in, plus $618,825 the market earned on top | $893,825 |
Computed with this calculator's default settings — open the tool above and you'll see the same numbers, then change any input to match your own plan.
Capture the employer match first
If your plan offers an employer match, it is the highest-priority contribution you can make — an immediate, guaranteed return that no market investment can reliably match. The rule of thumb is to contribute at least enough to earn the full match before sending savings anywhere else, because any unclaimed match is simply compensation left behind. Once the match is secured, you can decide how much further to push toward the IRS annual limit, which rises over time and includes extra catch-up room for savers aged 50 and older.
Watch the fees and the withdrawal rules
Two things deserve honest attention with 403(b) plans. First, their investment menus have historically leaned on annuity products that can carry higher costs than plain index funds, so check the expense ratio of each option — fees compound against you just as returns compound for you. Second, the account is built for retirement: withdrawals before age 59½ generally trigger ordinary income tax plus an early-withdrawal penalty. For a fuller view of how a 403(b) fits alongside other savings on your way to retirement, see ourretirement calculator.
Frequently asked questions
What is a 403(b)?
A 403(b) is a tax-deferred workplace retirement plan for employees of public schools, hospitals, churches, and other 501(c)(3) non-profit organisations — essentially the non-profit world’s equivalent of a 401(k). Contributions are made pre-tax, which lowers your taxable income in the year you make them, and the balance grows tax-deferred. You only pay income tax when you withdraw the money in retirement. Many plans also offer a Roth 403(b) option, where you contribute after-tax dollars and qualified withdrawals come out tax-free.
How is a 403(b) different from a 401(k)?
The two plans work almost identically — pre-tax contributions, tax-deferred growth, similar contribution limits, and the same withdrawal rules — but they serve different employers. A 401(k) is offered by for-profit companies, while a 403(b) is offered by public schools, hospitals, churches, and other non-profits. The most practical difference is the investment menu: 403(b) plans have historically leaned heavily on annuity products, which can carry higher fees than the index funds common in 401(k) plans, so it pays to check expense ratios carefully.
How much can I contribute to a 403(b)?
The IRS sets an annual limit on employee contributions to a 403(b), and that limit generally rises a little each year to keep pace with inflation. Workers aged 50 and older can add an extra catch-up contribution on top of the standard limit, and some long-serving employees of certain organisations may qualify for an additional catch-up. Employer matching contributions are counted separately and do not reduce how much you can personally put in, though there is an overall combined cap. Because the exact figures change over time, confirm the current year’s limits before maxing out.
What is the employer match worth?
An employer match is the single highest-priority part of any retirement plan because it is, quite literally, free money. If your employer matches a percentage of your salary when you contribute, every dollar of that match is an immediate, guaranteed return on your savings that no market investment can reliably beat. The general rule is to contribute at least enough to capture the full match before directing money anywhere else. Failing to contribute enough to earn the entire match means leaving part of your compensation on the table.
When can I withdraw from a 403(b)?
A 403(b) is designed for retirement, so withdrawals are intended for later in life. You can generally begin taking money out without penalty once you reach age 59½. Withdraw earlier than that and you will usually owe ordinary income tax on the amount plus an additional early-withdrawal penalty, with only limited exceptions. Because the account grows tax-deferred, the longer you leave the balance invested, the more compounding works in your favour — early withdrawals not only trigger taxes and penalties but also cut short years of potential growth.
Disclaimer: This calculator is foreducation and illustration only. Projections assume a constant rate of return and steady contributions, which real markets and real budgets rarely deliver, and contribution limits and tax rules change over time. The figures it produces are not financial advice or a guarantee of future results. Nothing here is investment, tax, or retirement-planning advice.