(1) All employees who first become employed by an employer in an eligible position on or after March 1, 2002, for state agencies or institutes of higher education, or September 1, 2002, for other employers, shall have a period of ninety days to make an irrevocable choice to become a member of plan 2 or plan 3. At the end of ninety days, if the member has not made a choice to become a member of plan 2, he or she becomes a member of plan 3 or plan 2 as follows:

(a) Becomes a member of plan 3 if first employed by an employer in an eligible position on or after March 1, 2002, but prior to July 1, 2020, for state agencies or institutions of higher education, or on or after September 1, 2002, but prior to July 1, 2020, for other employers;

(b) Becomes a member of plan 2 if first employed by an employer in an eligible position on or after July 1, 2020.

(2) For administrative efficiency, until a member elects to become a member of plan 3, or becomes a member of plan 3 by default pursuant to subsection (1) of this section, the member shall be reported to the department in plan 2, with member and employer contributions. Upon becoming a member of plan 3 by election or by default, all service credit shall be transferred to the member's plan 3 defined benefit, and all employee accumulated contributions shall be transferred to the member's plan 3 defined contribution account.