(a) Except as provided by Subsection (b), all retirement annuity payments, other benefit payments, and a member's accumulated contributions are unassignable and are exempt from execution, garnishment, attachment, and state and local taxation.
(b) The board of trustees by rule may authorize the retirement system to make distributions to pay the qualified health insurance premiums of a public safety officer in accordance with the provisions of Section 845, Pension Protection Act of 2006, Pub. L. No. 109-280.