Ohio Rev. Code Ann. § 4731.66
(A) Except as provided in sections 4731.67 and 4731.68 of the Revised Code, no holder of a license under this chapter to practice medicine and surgery, osteopathic medicine and surgery, or podiatric medicine and surgery shall refer a patient to a person for a designated health service if the license holder, or a member of the license holder's immediate family, has either of the following financial relationships with the person: