A 403(b) plan is a type of retirement savings account available to employees of certain non-profit organizations, public schools, and government entities. It allows participants to contribute a portion of their salary on a pre-tax basis, which can help reduce their taxable income for the year. The funds in a 403(b) can grow tax-deferred until withdrawal, typically during retirement. Employers may also contribute to a 403(b) plan, enhancing the savings potential for employees. Participants can choose from various investment options, including mutual funds and annuities, to help grow their retirement savings over time.