; and (ii) on or before the last day of the first plan year beginning after December 31, 2020, or such later date as the Secretary of the Treasury may prescribe. In the case of a governmental or collectively bargained plan to which subparagraph (B) or (C) of subsection (a)(4) applies, clause (ii) shall be applied by substituting the date which is 2 years after the date otherwise applied under such clause. (B) Conditions This subsection shall not apply to any amendment unless— (i) during the period— (I) beginning on the date the legislative or regulatory amendment described in paragraph (1)(A) takes effect (or in the case of a plan amendment not required by such legislative or regulatory amendment, the effective date specified by the plan); and (II) ending on the date described in subparagraph (A)(ii) (or, if earlier, the date the plan amendment is adopted), the plan is operated as if such plan amendment were in effect; and (ii) such plan amendment applies retroactively for such period. 502. Increase in penalty for failure to file (a) In general The second sentence of subsection (a) of section 6651 of the Internal Revenue Code of 1986 is amended by striking $205 and inserting $400 . (b) Effective date The amendment made by this section shall apply to returns the due date for which (including extensions) is after December 31, 2018. 503. Increased penalties for failure to file retirement plan returns (a) In general Subsection (e) of section 6652 of the Internal Revenue Code of 1986 is amended— (1) by striking $25 and inserting $100 ; and (2) by striking $15,000 and inserting $50,000 . (b) Annual registration statement and notification of changes Subsection (d) of section 6652 of the Internal Revenue Code of 1986 is amended— (1) by striking $1 both places it appears in paragraphs (1) and (2) and inserting $2 ; (2) by striking $5,000 in paragraph (1) and inserting $10,000