26 U.S.C. § 860B: Taxation of holders of regular interests

In determining the tax under this chapter of any holder of a regular interest in a REMIC, such interest (if not otherwise a debt instrument) shall be treated as a debt instrument. The amounts includible in gross income with respect to any regular interest in a REMIC shall be determined under the accrual method of accounting. the amount which would have been includible in the gross income of the taxpayer with respect to such interest if the yield on such interest were 110 percent of the applicable Federal rate (as defined in section 1274(d) without regard to paragraph (2) thereof) as of the beginning of the taxpayer’s holding period, over the amount actually includible in gross income with respect to such interest by the taxpayer. For special rules in determining inclusion of original issue discount on regular interests, see section 1272(a)(6).