Excerpt: The Internal Revenue Code sets limits on elective contributions made under retirement plans offered to employees of non-profit and governmental employers. Some non-profit and governmental employers can choose to offer one or more plans, including 403(b), 401(k), and section 457(b) plans. Generally, contributions made to 403(b) and 401(k) plans are aggregated when applying the contribution limits, while those made to section 457(b) plans are subject to separate limits.