Sec. 4.011. MEMBERSHIP OF FIRE CHIEF AND POLICE CHIEF. (a) Subject to Subsection (d) of this section, not later than the 30th day after the date a fire chief or a police chief of a municipality to which this Act applies assumes office, the fire chief or police chief may make an irrevocable election to not become a member of the fund.

(b) An election under this section must be made by delivering written notice of the election to the secretary of the board.

(c) A fire chief or police chief who does not make an election under this section becomes a member of the fund.

(d) A fire chief or police chief who was a member of the fund at any time during the two years preceding the date the fire chief or police chief assumes office may not make an election under this section.