Which of the following parties is able to participate in a 403(b) plan?

A sole proprietor typically does not qualify for a 403(b) plan, as this retirement plan is intended for employees of eligible institutions rather than self-employed individuals. Sole proprietors might consider other retirement plans, such as a SEP IRA or a solo 401(k), which cater specifically to self-employed persons.

Employees of public companies generally participate in 401(k) plans rather than 403(b) plans. While both types of plans are tax-advantaged retirement savings options, the 403(b) plan is specifically tailored for public educational institutions and certain nonprofit organizations, excluding typical public company employees.

Like public company employees, those working for private companies are usually eligible for 401(k) plans. The 403(b) plan does not extend to private sector employees, as it is designed for individuals employed by public schools, universities, and qualifying nonprofit organizations.