This document promulgates final regulations under section 403(b) of the Internal Revenue Code and under related provisions of sections 402(b), 402(g), 402A, and 414(c). The regulations provide updated guidance on section 403(b) contracts of public schools and tax- exempt organizations described in section 501(c)(3). These regulations will affect sponsors of section 403(b) contracts, administrators, participants, and beneficiaries.