Okla. Admin. Code § 715:10-1-8
Employees of charter schools created pursuant to 70 OS § 3-130 et seq. are eligible for membership in the Teachers' Retirement System providing the governing board of the charter school applies for membership for its regular employees. Upon approval of the application for membership by the Board of Trustees all employees of the charter school shall join the Teachers' Retirement System under the same membership eligibility rules applying to employees of other public schools. Employees of charter schools shall in all circumstances follow the rules applicable to other members of the Teachers' Retirement System. Employees of charter schools that do not apply or are not approved for membership in the Teachers' Retirement System shall not be eligible for retirement service credit for years of employment performed in a non-member status and such employees shall not be eligible to purchase service at anytime subsequent to such employment.
Okla. Admin. Code § 715:10-1-8