26 U.S.C. § 7491
Burden of proof
If, in any court proceeding, a taxpayer introduces credible evidence with respect to any factual issue relevant to ascertaining the liability of the taxpayer for any tax imposed by subtitle A or B, the Secretary shall have the burden of proof with respect to such issue.
Paragraph (1) shall not apply to any issue if any other provision of this title provides for a specific burden of proof with respect to such issue.
In the case of an individual taxpayer, the Secretary shall have the burden of proof in any court proceeding with respect to any item of income which was reconstructed by the Secretary solely through the use of statistical information on unrelated taxpayers.
Notwithstanding any other provision of this title, the Secretary shall have the burden of production in any court proceeding with respect to the liability of any individual for any penalty, addition to tax, or additional amount imposed by this title.
A prior section 7491, act Aug. 16, 1954, ch. 736, 68A Stat. 893, placed the burden of proof in establishing the applicability of an exemption upon the defendant in the case of marihuana offenses, prior to repeal by Pub. L. 91–513, title III, §§ 1101(b)(5)(A), 1103, 1105(a),
A prior section 7492, act Aug. 16, 1954, ch. 736, 68A Stat. 893, related to the enforceability of cotton futures contracts, prior to repeal by Pub. L. 94–455, title XIX, § 1952(n)(4)(A), (o),
A prior section 7493, act Aug. 16, 1954, ch. 736, 68A Stat. 893, provided that no person whose evidence is deemed material by the officer prosecuting on behalf of the United States in any case brought under any provision of subchapter D of chapter 39 of this title withhold his testimony because of complicity by him in any violation of subchapter D of chapter 39 of this title or of any regulation made pursuant to such chapter, but that such person called by such officer who testifies in the case be exempt from prosecution for any offense to which his testimony relates, prior to repeal by Pub. L. 91–452, title II, §§ 232, 260,
1998—Subsec. (a)(2). Pub. L. 105–277 inserted concluding provisions.
Amendment by Pub. L. 105–277 effective as if included in the provision of the Internal Revenue Service Restructuring and Reform Act of 1998, Pub. L. 105–206, to which such amendment relates, see section 4002(k) of Pub. L. 105–277, set out as a note under section 1 of this title.
Pub. L. 105–206, title III, § 3001(c),