Okla. Const. art. VII, § 11

(a) Judges and Supreme Court Justices shall receive for their services salaries provided by statute. The salaries of Judges and Justices shall not be diminished, but may be increased during their respective terms of office. Judicial officers may be paid such actual and necessary expenses as may be provided by statute. All basic salaries and expenses, or any portion thereof, of judges of District Courts shall be paid by the State unless otherwise provided by Statute with such additional salaries as may be provided by statute to be paid by the respective districts or counties.

(b) No Justices or Judges, except those of Municipal Courts, shall engage in the practice of law nor hold any other office or position of profit under the United States or this State or any municipal corporation or political subdivision of this State, nor shall hold office in any political party. Provided that the Judges of the Court on the Judiciary, the Court of Tax Review and the Court of Bank Review and the Judges of any other such Special Courts may serve in such capacities in addition to their other judicial office. Compensation for service in the National Guard or the armed forces of the United States for such periods of time as may be determined by rules of the Supreme Court shall not be deemed "profit".

(c) Notwithstanding the provisions of this Article relating to terms of office, the Legislature may provide by statute for a maximum age qualification for election or appointment to office and for the retirement of Justices and Judges automatically at a prescribed age or after a certain number of years of service, or both. The compensation, age of retirement and procedure for retirement shall be prescribed by statute. Any retired Justice or Judge may, in the discretion of the Supreme Court, be assigned to Judicial service. The compensation for such service shall be that to which the Justice or Judge is entitled in accordance with benefits as provided by statute.