deferred arrangement under subsection (k)(2) if no change had been made to such defined benefit plan and such other plan or arrangement. For purposes of the preceding sentence, consistency shall not be required with respect to employees who were subject to different benefit formulas under the defined benefit plan. (B) References to closed class of participants References to a closed class of participants and similar references to a closed class shall include arrangements under which 1 or more classes of participants are closed, except that 1 or more classes of participants closed on different dates shall not be aggregated for purposes of determining the date any such class was closed. (C) Highly compensated employee The term highly compensated employee has the meaning given such term in section 414(q). . (b) Participation requirements Section 401(a)(26) of such Code is amended by adding at the end the following new subparagraph: (I) Protected participants (i) In general A plan shall be deemed to satisfy the requirements of subparagraph (A) if— (I) the plan is amended— (aa) to cease all benefit accruals, or (bb) to provide future benefit accruals only to a closed class of participants, (II) the plan satisfies subparagraph (A) (without regard to this subparagraph) as of the effective date of the amendment, and (III) the amendment was adopted before April 5, 2017, or the plan is described in clause (ii). (ii) Plans described A plan is described in this clause if the plan would be described in subsection (o)(1)(C), as applied for purposes of subsection (o)(1)(B)(iii)(IV) and by treating the effective date of the amendment as the date the class was closed for purposes of subsection (o)(1)(C). (iii) Special rules For purposes of clause (i)(II), in applying section 410(b)(6)(C), the amendments described in clause (i) shall not be treated as a significant change in coverage under section 410(b)(6)(C)(i)(II). (iv) Spun-off plans For purposes of this subparagraph, if a portion of a plan described in clause (i) is spun off