Texas Government Code - GOV'T § 853.102. Eligibility for Prior Service

(1) became a member as an employee of a department of a municipality on the effective date of the department's participation in the retirement system;

(2) became a member as an employee of a department of a municipality before the fifth anniversary of the effective date of the department's participation and continued as an employee of a participating department of the municipality for at least five consecutive years after reemployment;  or

(3) became a member September 1, 1987, by virtue of Sections 852.101(a)(3) and (b) and has service before that date with a municipality that has adopted the provisions of Section 852.105.