Ohio Rev Code §3901.381(B)(1)

(B)(1) Unless division (B)(2) or (3) of this section applies, when a third-party payer receives from a provider or beneficiary a claim on the standard claim form prescribed in rules adopted by the superintendent of insurance under section 3902.22 of the Revised Code, the third-party payer shall pay or deny the claim not later than thirty days after receipt of the claim. When a third-party payer denies a claim, the third-party payer shall notify the provider and the beneficiary. The notice shall state, with specificity, why the third-party payer denied the claim.