Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 14, § 4

Any person appointed to any supervisory position in the department, whether or not the same shall be classified under chapter thirty-one, shall be a person with experience and skill in the field of taxation or in the field of the duties of such position. So far as feasible each appointment to each such position not so classified shall be made by promoting an employee of the department serving in a position so classified; and in such event upon termination of his service in such supervisory position such employee shall, at his request, be restored to his former position without loss of seniority and with full civil service status and rights therein; except that if such termination shall have been caused by his delinquency, his right to be so restored shall be determined in accordance with section forty-three of chapter thirty-one.

No position shall be created in the department, except the positions of deputy commissioner, chief of bureau and director of accounts unless and until the same shall be classified under chapter thirty-one; provided, however, that the secretary from time to time may, upon recommendation of the commissioner of revenue and the personnel administrator, exempt from the requirements of this paragraph positions with significant supervisory duties; provided, further, however, that at no time shall there be more than twenty-five positions in the aggregate not so classified because of any such exemption or exemptions.