Okla. Admin. Code § 590:10-11-2
The election to transport service into or out of OPERS is a voluntary action on the part of the member or former member. Only members or former members who have terminated participation with OPERS shall be eligible to transport service. In the event of an election to transport into OPERS, all service certified by Teachers' Retirement System shall be eligible to transport 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 transport 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 § 590:10-11-2