Ohio Revised Code Title XXXIX. Insurance § 3924.21

(A) As used in this section:

(B) If a beneficiary identifies on the billing statement of a provider or hospital any item or service for which the beneficiary was overcharged by more than five hundred dollars and the beneficiary notifies the third-party payer of the error at any time after the thirty-day period immediately following the date on which the third-party payer makes payment to the provider or hospital for the item or service, the provider or hospital shall refund to the beneficiary an amount equal to fifteen per cent of the amount overcharged.

(C) A provider or hospital shall not be required to comply with division (B) of this section if, at the time the third-party payer receives notice of the overcharge from the beneficiary, the provider, hospital, or third-party payer is in the process of correcting the error and such process can be documented.