The contributions required by paragraphs (b), (c), (e), (f), (g), and (h) of this subsection shall be made by a member for not more than twenty (20) years and thereafter shall be as provided in paragraph (a) of this subsection.
Member contributions which are picked up shall be treated in the same manner and to the same extent as member contributions made prior to the date on which member contributions were picked up by the participating employer. Member contributions so picked up shall be included in gross salary for purposes of determining benefits and contributions under the System.
The participating employer shall pay the member contributions from the same source of funds used in paying salary to the member, by effecting an equal cash reduction in gross salary of the member.
Okla. Stat. tit. 74, § 919.1