Benefits, rights, or features provided to closed classes
A defined benefit plan which provides benefits, rights, or features to a closed class of participants shall not fail to satisfy the requirements of subsection (a)(4) by reason of the composition of such closed class or the benefits, rights, or features provided to such closed class, if—
(i)#
for the plan year as of which the class closes and the 2 succeeding plan years, such benefits, rights, and features satisfy the requirements of subsection (a)(4) (without regard to this subparagraph but taking into account the rules of subparagraph (I)),
(ii)#
after the date as of which the class was closed, any plan amendment which modifies the closed class or the benefits, rights, and features provided to such closed class does not discriminate significantly in favor of highly compensated employees, and
(iii)#
the class was closed before April 5, 2017 , or the plan is described in subparagraph (C).