Ohio Revised Code Title I. State Government § 145.563

(A) The public employees retirement system may adjust an allowance or benefit payable under this chapter if an error occurred in calculation of the allowance or benefit;

(B) If any person who is a member, former member, contributor, former contributor, retirant, beneficiary, or alternate payee, as defined in section 3105.80 of the Revised Code, is paid any benefit or payment by the public employees retirement system, including any payment made to a third party on the person's behalf, to which the person is not entitled, the benefit or payment shall be repaid to the retirement system by the person or third party. A repayment required by this section may include a penalty or interest on the amount of the benefit or payment, as specified in rules adopted by the public employees retirement board. The rules shall specify the method for calculating a penalty or interest and the conditions under which a penalty or interest may be assessed.

If the person or third party fails to make the repayment, the retirement system shall withhold the amount or a portion of the amount due from any benefit or payment due the person or the person's beneficiary under this chapter, or may collect the amount in any other manner provided by law.