How to Set Up a 403(b): Eligibility, Contributions, and Enrollment

Setting up a 403(b) runs through your employer’s benefits office, not a brokerage. To open one, confirm your employer is a qualifying organization, decide how much of your paycheck you want to defer and whether those dollars go into a traditional pre-tax or Roth after-tax account, choose investments from the plan’s approved list, and submit a salary reduction agreement to payroll. For 2026, you can defer up to $24,500 of salary, with additional catch-up amounts if you’re 50 or older.1Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500

Confirm Your Employer Can Offer a 403(b)

Only certain organizations are allowed to sponsor these plans. Eligible sponsors are public schools, colleges, and universities; charities and nonprofits with 501(c)(3) tax-exempt status; churches and religious organizations; and cooperative hospital service organizations. Ministers qualify too, including self-employed ministers and chaplains at non-501(c)(3) employers who function as ministers in their work.2Internal Revenue Service. IRC 403(b) Tax-Sheltered Annuity Plans If your employer isn’t in one of those categories, a 403(b) isn’t available to you regardless of your job title.

If your employer offers a 403(b) to anyone on staff, federal law generally requires them to offer it to everyone. This is the universal availability rule, and it stops employers from excluding workers based on labels like part-time, seasonal, substitute teacher, or adjunct.3Internal Revenue Service. Issue Snapshot – 403(b) Plan – The Universal Availability Requirement Every eligible employee must get at least one opportunity per plan year to start or change contributions. A few narrow exceptions apply: workers normally logging under 20 hours per week, students performing certain campus services, and nonresident aliens with no U.S.-source income. Churches and church-controlled organizations are exempt from the universal availability rule entirely. If you don’t fit one of those exceptions and colleagues are being enrolled while you aren’t, raise it with HR.

Decide Between Traditional and Roth Contributions

Many plans offer both. Traditional contributions come out of your paycheck before income tax, lowering your taxable income now; you pay tax when you withdraw the money in retirement. Roth contributions come out after tax, and qualified withdrawals in retirement are tax-free.

Which one fits depends on whether your tax rate is likely higher now or in retirement. Workers earlier in their careers, when income is lower, often lean Roth. Workers closer to peak earnings often prefer the immediate deduction of traditional. You can split contributions between both as long as the combined total stays within the annual limit.

One rule to know for 2026: under SECURE 2.0, if you earned more than $145,000 in FICA wages the prior year, any catch-up contributions you make (the extra amount allowed at age 50 and older) must go into Roth. Below that threshold, catch-up dollars can be pre-tax or Roth at your choice.

Pick a Contribution Amount

The 2026 baseline elective deferral limit is $24,500 if you’re under 50.1Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500 Several catch-ups can push that number higher:

The 15-year and age-based catch-ups can sometimes stack, but the 15-year piece is applied first. Your plan administrator can calculate the exact ceiling if you’re near either limit.

There is also an overall cap that includes your deferrals plus any employer contributions. For 2026, total annual additions cannot exceed $72,000 or 100% of your includible compensation, whichever is less.6Internal Revenue Service. 2026 Amounts Relating to Retirement Plans and IRAs, as Adjusted for Changes in Cost-of-Living Most employees won’t reach it through their own deferrals alone.

Capture the Employer Match First

Many 403(b) plans include employer contributions on top of your deferrals. These may be matching contributions tied to what you put in, or nonelective contributions the employer makes regardless of what you defer.7Internal Revenue Service. 403(b) Plan Fix-It Guide – Your 403(b) Plan Doesn’t Limit the Total Employer and Employee Contributions to Not Exceed the IRC Section 415(c) Limits If a match is offered, set your contribution at least high enough to capture the full match before any other savings decision. Employer contributions always go into a traditional pre-tax bucket, even if your own contributions are Roth, and those dollars will be taxed when you eventually withdraw them.

Choose Your Investments

A 403(b) can hold only three types of investment vehicles:2Internal Revenue Service. IRC 403(b) Tax-Sheltered Annuity Plans

  • Annuity contracts purchased through insurance companies. These are why 403(b)s are sometimes called tax-sheltered annuities. They can guarantee income payments in retirement but often carry higher fees than mutual funds.
  • Custodial accounts invested in mutual funds. These work more like what you’d see in a typical 401(k) and generally have lower costs.
  • Retirement income accounts, which are available only to church employees and can hold either annuities or mutual funds.

Your employer decides which providers and funds appear on the menu. Some plans offer a single insurance company with a limited annuity lineup; others give you a choice of several providers with dozens of mutual funds. Compare expense ratios and historical performance before you commit. Your plan administrator must provide fee disclosures at least once a year, including total annual operating expenses for each option and any administrative fees charged to your account.8eCFR. Fiduciary Requirements for Disclosure in Participant-Directed Individual Account Plans

Gather Your Documents

Enrollment moves faster if you show up with everything ready. You’ll need your Social Security number and date of birth for tax reporting and identity verification, plus contact details for anyone you want to name as a beneficiary: full legal name, relationship, and date of birth.

If you’re married, check your plan’s beneficiary rules before picking anyone other than your spouse. Some 403(b) plans that fall under ERISA require your spouse to be the primary beneficiary unless your spouse signs a written waiver.9Internal Revenue Service. Fixing Common Plan Mistakes – Failure to Obtain Spousal Consent Governmental and church plans are typically exempt, but confirm with HR before assuming you can name a non-spouse beneficiary without written spousal consent.

Decide two things in advance so enrollment doesn’t stall: the amount you want to contribute (a dollar figure per paycheck or a percentage of salary) and how you want that money invested across the plan’s options.

Submit the Salary Reduction Agreement

The salary reduction agreement is the document that opens the account. It authorizes payroll to divert part of your gross pay into your 403(b) before you ever see it.10Internal Revenue Service. 403(b) Plan Fix-It Guide – You Didn’t Give All Employees of the Organization the Opportunity to Make a Salary Deferral On the agreement, you’ll specify the deferral amount, whether contributions are traditional or Roth, and which investment provider and funds you’ve chosen. Most employers run this through an online benefits portal; some still use paper forms routed through HR.

Once payroll processes the agreement, deductions typically start within one or two pay cycles. Check your next pay stub to confirm the right amount is coming out, then log into your investment provider’s site to make sure the money is landing in the funds you picked. Catching a misrouted contribution in the first month is easy. Fixing it six months later is not.

If Your Employer Enrolls You Automatically

If your employer established its 403(b) on or after December 29, 2022, SECURE 2.0 likely requires automatic enrollment starting with the 2025 plan year. Under that mandate, new employees are enrolled at a default contribution rate of at least 3% (but no more than 10%) of pay, and the rate rises by 1% each year until it reaches at least 10%. You can opt out or change your contribution rate at any time, but if you do nothing, deferrals begin on their own.

Several plan types are exempt from the auto-enrollment requirement, including church plans, governmental plans, and plans sponsored by employers with 10 or fewer employees. If your employer’s plan predates December 29, 2022, automatic enrollment is optional. Even if you’re auto-enrolled, it’s still worth walking through the same decisions above: the default rate may not capture the full employer match, and the default investment may not be the one you’d choose on your own.