This document contains final regulations providing guidance relating to applicable defined benefit plans. Applicable defined benefit plans are defined benefit plans that use a lump sum-based benefit formula, including cash balance plans and pension equity plans, as well as other hybrid retirement plans that have a similar effect. These regulations provide guidance relating to certain provisions that apply to applicable defined benefit plans that were added to the Internal Revenue Code (Code) by the Pension Protection Act of 2006, as amended by the Worker, Retiree, and Employer Recovery Act of 2008. These regulations affect sponsors, administrators, participants, and beneficiaries of these plans.