A 403(b) plan is a U.S. tax-advantaged retirement savings plan available for public education organizations, some non-profit employers, cooperative hospital service organizations, and self-employed ministers in the United States. It has tax treatment similar to a 401(k) plan. Employee salary deferrals into a 403(b) plan are made before income tax is paid and allowed to grow tax-deferred until the money is taxed as income when withdrawn from the plan.