A 403(b) is a tax-advantaged retirement plan for employees of public schools, certain nonprofits, and religious organizations. It works similarly to a 401(k) but is designed for the public and nonprofit sectors.
403(b) vs 401(k)
Same contribution limits ($23,000 in 2024)
403(b) has a special "15-year rule" — employees with 15+ years of service may contribute an extra $3,000/year (up to $15,000 lifetime)
Investment options may be more limited (often only annuities and mutual funds)