(a) Except as provided by Subsection (c), (d), or (e), eligibility under § 1601.101 begins on the first day of the calendar month that begins after the 90th day after the date the employee performs services for a system.
(b) Except as provided by Subsection (c), eligibility under § 1601.102, for an individual who does not retire at the end of the last month for which the individual is on the payroll of a system before retirement, begins on the first day of the calendar month that begins after the 90th day after the date the individual retires.

(c) The waiting period established by Subsections (a) and (b) applies only to the determination of initial eligibility to participate in the group health benefits program and does not apply to the determination of initial eligibility to participate in optional coverages under the uniform program.
(d) Notwithstanding Subsection (a), eligibility under § 1601.101 may not begin earlier than the first day that an employee performs services for a system if any amount paid for premium incurred before the date specified under Subsection (a) for the employee and any dependents of the employee is paid from money not appropriated from the general revenue fund, in accordance with policies and procedures established by the system.
(e) Eligibility under § 1601.101 for an employee reemployed under Chapter 613, Government Code, begins on the first day of reemployment on which the employee performs services for a system.