§ 644. Taxable year of trusts(a) In general
(b) Exception for trusts exempt from tax and charitable trusts
(Added Pub. L. 99–514, title XIV, § 1403(a), Oct. 22, 1986, 100 Stat. 2713, § 645; renumbered § 644, Pub. L. 105–34, title V, § 507(b)(1), Aug. 5, 1997, 111 Stat. 856.)