Mass. Gen. Laws ch. 31 § 40
If a permanent employee shall become separated from his position because of lack of work or lack of money or abolition of his position, his name shall be placed by the administrator on a reemployment list, or if a permanent employee resigns for reasons of illness his name shall be placed on such list upon his request made in writing to the administrator within two years from the date of such resignation.
The names of persons shall be set forth on the reemployment list in the order of their seniority, so that the names of persons senior in length of service at the time of their separation from employment, computed in accordance with section thirty-three, shall be highest. The name of a person placed on such reemployment list shall remain thereon until such person is appointed as a permanent employee after certification from such list or is reinstated, but in no event for more than two years. The administrator, upon receipt of a requisition, shall certify names from such reemployment list prior to certifying names from any other list or register if, in his judgment, he determines that the position which is the subject of the requisition may be filled from such reemployment list.
If the position of a permanent employee is abolished as the result of the transfer of the functions of such position to another department, division, board or commission, such employee may elect to have his name placed on the reemployment list or to be transferred, subject to the approval of the administrator, to a similar position in such department, division, board or commission without loss of seniority, retirement or other rights, notwithstanding the provisions of section thirty-three.
Mass. Gen. Laws ch. 31, § 40