Ohio Rev. Code Ann. § 3307.252

A member of the state teachers retirement system who elects to participate in an STRS defined contribution plan shall be ineligible for any benefit or payment under the STRS defined benefit plan and, except as provided in section 3307.25 of the Revised Code, shall be forever barred from claiming or purchasing service credit with the system or any other Ohio state retirement system for service covered by the election.