Okla. Stat. tit. 57 § 530
It is the intent of the State Legislature that all new prisoners sentenced to the custody of the Department of Corrections will be processed through the Lexington Assessment and Reception Center or at a place determined by the Director of the Department of Corrections. The Department of Corrections shall ensure administration of a risk and needs assessment, as defined in Section 502 of this title, physical and psychological examinations, mental health and substance abuse screens, inventory vocational skills, and assess educational and training needs. A risk and needs assessment shall not be required for any inmate who had a risk and needs assessment administered by personnel certified by the Department of Mental Health and Substance Abuse Services within six (6) months of being sentenced to the custody of the Department of Corrections. The Department of Corrections shall determine initial security and custody classifications, plan for immediate or possible future assignment to an institution, community treatment center or other alternative to incarceration authorized by law, provide orientation and instruction with respect to rules and procedures for prisoners, and perform other such activities deemed necessary by the Department of Corrections.
Okla. Stat. tit. 57, § 530