(1) The board shall administer the assets of the pension trust funds as provided in Article VIII, section 15, of the Montana constitution, subject to the specific provisions of chapters 2, 3, 5 through 9, and 13 of this title.
(2) Benefits and refunds to eligible recipients are payable pursuant to a contract as contained in statute. The contract is entered into on the first day of a member's covered employment and may be enhanced by the legislature. Unless specifically provided for by statute, the contract does not contain revisions to statutes after the time of retirement or termination of membership.