(1) (a) Retirees from the judicial division may return to temporary judicial duties pursuant to the provisions of section 5 (3) of article VI of the Colorado state constitution and section 13-4-104.5, C.R.S., while receiving service retirement benefits.

(b) Notwithstanding the provisions of section 24-51-1101, upon written agreement with the chief justice of the Colorado supreme court prior to retirement, a member of the judicial division may perform, during retirement, assigned judicial duties without pay for not less than sixty or more than ninety days each year and shall receive a benefit increase equal to not less than twenty percent or more than thirty percent of the current monthly salary of judges serving in the same position as that held by the retiree at the time of retirement. Such agreement shall be for a period of not more than three years. A retiree may enter into subsequent agreements. The aggregate of these agreements shall not exceed twelve years, except at the discretion of the Colorado supreme court.

(2) Within five years after retirement, a retiree from the judicial division who did not enter into an agreement as provided for in subsection (1) of this section prior to retirement may enter into such a written agreement within thirty days prior to each anniversary date of retirement. Upon entering into such agreement, the retirement benefit shall include such benefit increase as provided for in subsection (1) of this section.

(2.5) A retiree from the judicial division, who has entered into an agreement pursuant to subsection (1) of this section, may take a leave of absence from temporary judicial duties to be performed under such agreement, with a cessation of the increase specified in subsection (1) of this section. Within thirty days prior to each anniversary date of retirement, and upon written request to and approval by the chief justice, a retiree, who has taken a leave of absence, may reenter into such agreement to perform assigned temporary judicial duties. Upon reentering into such agreement, the retirement benefit shall include the benefit increase specified in subsection (1) of this section.

(3) If a written agreement is entered into pursuant to the provisions of this section, and notice is received from the chief justice of the refusal of the retiree to accept a temporary assignment without just cause, the retirement benefit shall be recalculated to reduce the benefit to the amount payable without the increase specified in subsection (1) of this section. The reduction shall be effective on the first day of the month following such refusal.

(4) Increases in the retirement benefit pursuant to the provisions of this section shall be reimbursed to the judicial division trust fund by an annual appropriation by the general assembly to the judicial department for payment into the judicial division trust fund.

(5) Nothing in this section shall be construed to require a retiree from the judicial division to enter into an agreement to perform temporary judicial duties.

(6) Retirees from the judicial division include justices and judges who have retired from the supreme court, the court of appeals, district courts, county courts, probate courts, and juvenile courts.