calendar year 2016 in subparagraph (A)(ii) thereof. (6) Section 15 not to apply Section 15 shall not apply to any change in a rate of tax by reason of this subsection. . (b) Due diligence tax preparer requirement with respect to head of household filing status Subsection (g) of section 6695 is amended to read as follows: (g) Failure to be diligent in determining eligibility for certain tax benefits Any person who is a tax return preparer with respect to any return or claim for refund who fails to comply with due diligence requirements imposed by the Secretary by regulations with respect to determining— (1) eligibility to file as a head of household (as defined in section 2(b)) on the return, or (2) eligibility for, or the amount of, the credit allowable by section 24, 25A(a)(1), or 32, shall pay a penalty of $500 for each such failure. . (c) Effective date The amendments made by this section shall apply to taxable years beginning after December 31, 2017. 11002. Inflation adjustments based on chained CPI (a) In general Subsection (f) of section 1 is amended by striking paragraph (3) and by inserting after paragraph (2) the following new paragraph: (3) Cost-of-living adjustment For purposes of this subsection— (A) In general The cost-of-living adjustment for any calendar year is the percentage (if any) by which— (i) the C-CPI-U for the preceding calendar year, exceeds (ii) the CPI for calendar year 2016, multiplied by the amount determined under subparagraph (B). (B) Amount determined The amount determined under this clause is the amount obtained by dividing— (i) the C-CPI-U for calendar year 2016, by (ii) the CPI for calendar year 2016. (C) Special rule for adjustments with a base year after 2016 For purposes of any provision of this title which provides for the substitution of a year after 2016 for 2016 in subparagraph (A)(ii), subparagraph (A) shall be applied by substituting the C-CPI-U for calendar year 2016 for the CPI for calendar year 2016 and all that follows in clause (ii) thereof. . (b) C-CPI-U