(a) Any retired justice of the supreme court, retired judge of the court of appeals, retired district judge or retired associate district judge may be designated and assigned to perform such judicial service and duties as such retired justice or judge is willing to undertake. Designation and assignment of a retired justice or judge in connection with any matter pending in the supreme court shall be made by the supreme court. Designation and assignment of a retired justice or judge in connection with any matter pending in any other court, including any court located within the judicial district in which the justice or judge resides, or to perform any other judicial service or duties shall be made by the chief justice of the supreme court. Any such judicial service or duties shall include necessary preparation and other out-of-court judicial service for hearings or for deciding matters or cases in conjunction with the judicial services and duties assigned under this section. Any designation and assignment may be revoked in the same manner and all such designations and assignments and revocations shall be filed of record in the office of the clerk of the court to which such assignment is made.

(b) A retired justice or judge so designated and assigned to perform judicial service or duties shall have the power and authority to hear and determine all matters covered by the assignment.

(c) Except as otherwise provided in this section, each retired justice or judge who performs judicial service or duties under this section shall receive (1) per diem compensation at the rate of per diem compensation in effect under Kan. Stat. Ann. § 46-137a, and amendments thereto, (2) a per diem subsistence allowance at the per diem subsistence allowance rate in effect under Kan. Stat. Ann. § 46-137a, and amendments thereto, (3) a mileage allowance at the rate fixed under Kan. Stat. Ann. § 75-3203a, and amendments thereto, and (4) all actual and necessary expenses for other than subsistence or travel, including necessary stenographic assistance, as may be incurred in performing such service or duties.

(d) No retired justice or judge shall be entitled to receive per diem compensation under this section for any day in a fiscal year after the date that the total of (1) the amount of per diem compensation earned under this section during that fiscal year and (2) the amount of the retirement annuity payable to such retired justice or judge for that fiscal year under the retirement system for judges, becomes equal to or more than the amount of the current annual salary of a district judge paid by the state under Kan. Stat. Ann. § 75-3120g, and amendments thereto, but such retired justice or judge shall receive the subsistence allowance, mileage allowance and actual and necessary expenses as provided under this section after such date.

(e) As used in this section, a retired justice or judge shall not include those justices or judges who were not retained in office, were not reelected to office, have been impeached from office or removed by the supreme court from office.