This document contains final regulations that provide guidance under Internal Revenue Code (Code) section 664 on the tax effect of unrelated business taxable income (UBTI) on charitable remainder trusts. The regulations reflect the changes made to section 664(c) by section 424(a) and (b) of the Tax Relief and Health Care Act of 2006. The regulations affect charitable remainder trusts that have UBTI in taxable years beginning after December 31, 2006.