Ohio Rev. Code Ann. § 3309.253

A member of the school employees retirement system who elects to participate in a plan established under section 3309.81 of the Revised Code shall be ineligible for any benefit or payment under sections 3309.18 to 3309.70 of the Revised Code and shall be forever barred from claiming or purchasing service credit with any state retirement system, as defined in section 145.30 of the Revised Code, for service covered by the election.