Sec. 5.01. MEMBERSHIP IN COMBINED PENSION PLAN. (a) Except as provided by Subsection (a-1) of this section, the membership of the combined pension plan is composed of the following persons:

(1) Group A members:

(A) police officers or fire fighters who are on active service and who as of February 28, 1973, had filed a written statement with the pension system of their desire to participate in either the old plan or Plan A;

(B) police officers and fire fighters who are on active service and who were employed and receiving compensation from the city as a police officer or a fire fighter before March 1, 1973, and who made contributions to either the old plan or Plan A attributable to any period of employment before March 1, 1973; and

(C) except as provided by Subsection (b) of this section, persons who elect to become Group A members under that subsection; and

(2) Group B members:

(A) police officers and fire fighters who are on active service and who were formerly members of either the old plan or Plan A and who, as of April 30, 1973, had filed a written statement with the pension system of their desire to participate in Plan B;

(B) police officers and fire fighters who are on active service and who on or after March 1, 1973, and before January 1, 1993, became members of Plan B;

(C) as a condition of employment, any police officer or fire fighter who is initially employed as a police officer or a fire fighter by the city on or after January 1, 1993;

(D) as a condition of return to active service and except as provided by Subsection (b) of this section, former members of the old plan or Plan A who left active service before March 1, 1973;

(E) as a condition of return to active service and except as provided by Subsection (c) of this section, former Group B members who are no longer on active service, whether or not the persons were ever a member of the old plan, Plan A, or the combined pension plan;

(F) Group A members who are on active service and meet the requirements and make an election under Subsection (d) of this section; and

(G) persons who are on active service and make an election under Subsection (e) of this section.

(a-1) Group A or Group B members do not include any employee of the city who is:

(1) required by ordinance or who elects, in accordance with an ordinance, to participate in an alternative benefit plan established under Section 3.01(j-1)(2) of this article based on an evaluation under Section 3.01(j-5)(2) of this article; or

(2) required by ordinance to participate in an alternative benefit plan established under Section 810.002, Government Code.

(b) A person who has received an old plan, Plan A, or combined pension plan retirement or disability pension on or after March 1, 1973, may, if the person returns to active service, elect to participate as a Group A or Group B member by filing a written application for membership with the executive director not later than 60 days after the date of return to active service. If the person described by this subsection does not elect to become a Group A or Group B member, the person shall on leaving active service receive a retirement pension in an amount that is unadjusted for the period of return to active service if the person meets all of the requirements of Group A membership.

(c) A Group B pensioner who was never a member of the old plan, Plan A, or the combined pension plan before January 1, 1993, may, if the person returns to active service, elect to become a Group B member by filing a written application for membership with the executive director not later than 60 days after the date of return to active service. If the person described by this subsection does not elect to again become a Group B member, on leaving active service, if the person meets all applicable requirements of this article, the person shall receive benefits in an amount equal to the amount the person was receiving as of the day before the day the person returned to active service, and the person's base pension shall be the same as the base pension originally computed before the return to active service.

(d) A person who is on active service and is a Group A member may, before the person participates in DROP, irrevocably elect to become a Group B member by filing a written application with the executive director. On and after the filing of the application, the Group A member shall make contributions to the fund at the rate applicable to Group B members. However, the contributions do not, by themselves, establish Group B membership. Group B membership is contingent on the satisfaction of the following conditions:

(1) the person must, before the person elects to participate in DROP, pay an amount to the fund equal to the difference between the contributions the person would have made to the fund had the person been a Group B member for the entire period the person could otherwise have been a Group B member before making application for membership and the contributions the person actually made during that period, plus interest calculated in accordance with procedures adopted by the board from time to time; and

(2) the payments described by this subsection must be completed before the earlier of the date on which the person begins participation in DROP or leaves active service in accordance with procedures adopted by the board from time to time.

(d-1) If the fund does not receive payment under Subsection (d)(1) of this section by the date prescribed by Subsection (d)(2) of this section, all payments made under Subsection (d)(1) of this section, as well as those contribution amounts paid by the person after the person's application for Group B membership that are in excess of the Group A member contribution rate, shall be returned without accrued interest to the person, or in the event of the person's death to the person's designee, as applicable.

(e) A person who is on active service and has never been a member of any plan within the pension system may elect to become a Group B member on a prospective basis by filing a written application for membership with the executive director.