807 CMR, § 4.01.1
Teacher Position. A "teacher position" means regular employment, on at least a half-time basis, in a position that satisfies the MTRS' eligibility criteria at 807 CMR 4.02. A "teacher position" shall not include day-to-day or short-term employment.
Day-to-day Employment : Employment on a day-to-day basis means any employment on an intermittent basis. Day-to-day employment is not regular employment.
Short-term Employment. Short-term employment is substitute, part-time, temporary or seasonal employment of less than six calendar months' duration.
Separation from Service : "Separation from service" for a teacher occurs at the moment they cease to be regularly employed in a teacher position with their employer. This occurs upon:
(a) Their resignation from that employer;
(b) Their failure to be re-elected or re-appointed in a teacher position by that employer;
(c) Their removal or discharge from their position;
(d) Their commencement of service in a position other than a teacher position;
(e) Their commencement of day-to-day or short-term employment;
(f) The beginning of any period of an authorized unpaid leave of absence beyond one year, which is not:
1. Leave that is due to mental or physical incapacity for duty or to permit such member to perform their duties as a member of a retirement board, as provided for in M.G.L. c. 32, § 3, or
2. Leave to serve as a representative of an employee organization, as provided for in M.G.L. c. 32, § 28K;
(g) Their retirement.
For purposes of determining whether there has been a separation from service, an existing member of the MTRS, employed under a ten-month, or school year contract, will not be considered separated from service during the summer months between school years so long as they return to regular employment in a teacher position with their same employer, beginning with the start of the next school year.
807 CMR, § 4.01.1