; except that the base period taken into account shall be the calendar quarter beginning July 1, 2020. . (c) Effective date The amendments made by this section shall apply to years beginning after December 31, 2020. 109. Multiple employer 403 (b) plans (a) In general Section 403(b) of the Internal Revenue Code of 1986 is amended by adding at the end the following new paragraph: (15) Multiple employer plans (A) In general Except in the case of a church plan, this subsection shall not be treated as failing to apply to an annuity contract solely by reason of such contract being purchased under a plan maintained by more than 1 employer. (B) Treatment of employers failing to meet requirements of plan (i) In general In the case of a plan maintained by more than 1 employer, this subsection shall not be treated as failing to apply to an annuity contract held under such plan merely because of one or more employers failing to meet the requirements of this subsection if such plan satisfies rules similar to the rules of section 413(e)(2) with respect to any such employer failure. (ii) Additional requirements in case of non-governmental plans A plan shall not be treated as meeting the requirements of this subparagraph unless the plan meets the requirements of subparagraph (A) or (B) of section 413(e)(1), except in the case of a multiple employer plan maintained solely by any of the following: A State, a political subdivision of a State, or an agency or instrumentality of any one or more of the foregoing. . (b) Annual registration for 403 (b) multiple employer plan Section 6057 of such Code is amended by redesignating subsection (g) as subsection (h) and by inserting after subsection (f) the following new subsection: (g) 403 (b) multiple employer plans treated as one plan In the case of annuity contracts to which this section applies and to which section 403(b) applies by reason of the plan under which such contracts are purchased meeting the requirements of paragraph (15) thereof, such plan shall be treated as a single plan