This document contains final regulations under sections 401(k), 402(g), 402A, and 408A of the Internal Revenue Code (Code) relating to designated Roth accounts. These final regulations provide guidance concerning the taxation of distributions from designated Roth accounts under qualified cash or deferred arrangements under section 401(k). These final regulations will affect administrators of, employers maintaining, participants in, and beneficiaries of section 401(k) and section 403(b) plans, as well as owners and beneficiaries of Roth IRAs and trustees of Roth IRAs.