is amended by adding at the end the following new subsection: (f) Limitation on access of persons other than Internal Revenue Service officers and employees No person other than an officer or employee of the Internal Revenue Service shall be designated under section 6103(n) to receive any books, papers, records, or other data obtained pursuant to this section, other than for the sole purpose of serving as an expert, and no person other than an officer or employee of the Internal Revenue Service or the Office of Chief Counsel may question a witness under oath whose testimony was obtained pursuant to this section. . (b) Effective date (1) In general Except as provided in paragraph (2), the amendment made by this section shall take effect on the date of the enactment of this Act. (2) Application to contracts in effect The amendment made by this section shall apply to any contract in effect under section 6103(n) of the Internal Revenue Code of 1986, pursuant to temporary Treasury Regulation section 301.7602–1T proposed in Internal Revenue Bulletin 2014–28, Treasury Regulation section 301.7602–1(b)(3), or any similar or successor regulation, that is in effect on the date of the enactment of this Act.