Ohio Revised Code Title XXXIII. Education Libraries § 3307.24

The state teachers retirement board may deny the right to contribute or the right to become members to any class of teachers whose compensation is partly paid by the state, who are not serving on a per annum basis, who are on a temporary basis, or who are not required to have an educator license or registration, and it may also make optional with teachers in any such class their right to contribute, or their right to individual entrance into membership.

The state teachers retirement board may at any time deny the right to contribute or the right to membership to any teacher whose compensation, though disbursed by an employer, is reimbursed to the employer, in whole or in part, from other than public funds.