Mass. Gen. Laws ch. 44 § 35
Cities, towns, districts, and regional school districts shall conduct periodic audits of their accounts, according to any standards established by the director under section 38, and shall engage for that purpose a professional auditing firm or other independent accountant as may be necessary or appropriate. The chief executive officer of a city or town, the prudential committee, if any, otherwise the commissioners, of a district, or the regional district school committee may also cause an audit to be performed when, in their opinion, the condition of the accounts is such as to warrant the making of such audit necessary and useful.
Notwithstanding any general or special law that provides for the director to cause an annual or other periodic audit of a regional or other governmental unit created within 1 or more cities or towns of the commonwealth to provide public services or conveniences, such governmental unit shall be considered a district for purposes of conducting a periodic audit under this section and sections 38, 39, 40, 41 and 42. Upon the completion of each audit, a copy shall be sent to the chief executive officer of each city or town which is a member of the governmental unit. The cost of each audit shall be a current expense of the governmental unit and shall be apportioned among the several cities and towns that are members of the unit in the same manner as other such expenses.
Mass. Gen. Laws ch. 44, § 35