Mass. Gen. Laws ch. 211A § 17
The chief justice of the appeals court may, subject to the approval of the chief justice of the supreme judicial court, grant a leave of absence for study, research, teaching, or such other reason as said chief justice of the appeals court deems appropriate to the improved administration of justice, to an associate justice of said appeals court, said leave to be for a period not to exceed one year. Any judge who is authorized to take a leave of absence shall not receive any pay during the period of such leave of absence. Provided, however, that time spent on a leave of absence shall be credited to the judge for retirement purposes; provided, further, that for the purposes of eligibility for life insurance and health plans available under chapter thirty-two A, said judge shall be considered an active employee. The chief justice in approving such leaves shall consider the speedy dispatch of judicial business. The chief justice of the appeals court, in consultation with the supreme judicial court, shall establish and promulgate standards governing the approval of such leaves including procedures for the submission and disposition of requests for leave.
No leave of absence under this section shall be granted prior to the seventh year of service or within one year of retirement. A justice granted a leave of absence under this section shall not be eligible to take another leave of absence until the expiration of seven years following his return to judicial duties.
All statutory requirements and rules of court pertaining to justices shall continue to be applicable to a justice while he is on a leave of absence pursuant to this section.
Mass. Gen. Laws ch. 211A, § 17