Credit for out-of-state service is limited to a maximum of five (5) years. This includes credit for service both before and after July 1, 1943. No credit may be given for any year of out-of-state service which duplicates any other credit already granted or in which a year of creditable service is available for service in the public schools of Oklahoma. The member must have two (2) years of creditable Oklahoma service after each year of out-of-state service purchased. Military service credit cannot count as employment in obtaining credit for out-of-state service credit.
Okla. Admin. Code § 715:10-5-22