There are three clearinghouse payers that are also contracted with the OKHCA to process claims for Oklahoma Medicaid clients. The three MCO payers require prior authorization for very few OPBH services. All three should have the same requirements for that, and one of them provides an online tool to look up services to see if prior authorization is required:
https://www.aetnabetterhealth.com/oklahoma/providers/prior-authorization.html