(1) Notwithstanding any other law to the contrary and except as provided in subsection (b), any current or former member of the retirement system or of a superseded system who accepts, or is elected to, a position on or after July 1, 2018, for which membership in the retirement system is otherwise optional shall become a member of the retirement system as a condition of employment.
(2) Subsection (a) shall not apply to an employee having optional membership who was employed by a political subdivision on the date the political subdivision elected to extend retirement coverage to the employee, unless the employee was a member or former member of a preexisting defined benefit plan maintained by that political subdivision. For purposes of this section, “political subdivision” means any entity authorized to participate in the retirement system pursuant to part 2 of this chapter.
(3) This section shall not apply to retired members of the retirement system or of a superseded system who return to service in a position covered by the retirement system as provided in § 8-36-805, § 8-36-810, § 8-36-818, or § 8-36-821.