Texas Government Code - GOV'T § 803.003. Construction of Chapter

(a) The provisions of this chapter are exceptions to the other laws governing retirement systems to which this chapter applies and prevail over those laws to the extent of explicit conflict, but this chapter must be construed strictly as against those laws.

(b) Notwithstanding any other law, a person who is involuntarily transferred to a position included in the coverage of a retirement system governed by Chapter 101, Acts of the 43rd Legislature, 1st Called Session, 1933 (Article 6243b, Vernon's Texas Civil Statutes), from a position included in a retirement system operated by a municipality that does not participate in a statewide retirement system governed by Chapter 101, Acts of the 43rd Legislature, 1st Called Session, 1933 (Article 6243b, Vernon's Texas Civil Statutes), may make an irrevocable election at the time of the transfer to continue membership in the municipal retirement system.  An involuntary transfer is determined by the employment rules that apply to the person immediately before the time of the involuntary transfer.