Okla. Admin. Code § 590:10-11-11
The election to transfer state portable service into or out of OPERS is a voluntary action on the part of the member. Only current members of OPERS or Teachers' shall be eligible to transfer state portable service. In the event of an election to transfer state portable service into OPERS, all service certified by Teachers' Retirement System shall be eligible to transfer into OPERS, subject to any statutory limitations. OPERS shall certify to Teachers' Retirement System all service credited to the member or former member as of the date of election. Once the election to transfer state portable service is successfully completed, all service credit of said member under OPERS shall be cancelled, including service not accepted by Teachers' Retirement System.
Okla. Admin. Code § 590:10-11-11